If you are looking for a cozy baked dinner with tender potatoes, juicy shrimp, plenty of garlic, and a rich creamy cheese sauce, this Creamy Garlic Shrimp & Potato Gratin is an excellent recipe to make. Thinly sliced potatoes are layered with a silky garlic cream sauce, Parmesan, mozzarella, and tender shrimp, then baked until the potatoes are soft and the top is golden and bubbling.
This recipe is perfect for family dinners, holidays, date nights, or weekends when you want something a little more special than an ordinary potato casserole. The potatoes absorb the creamy garlic sauce as they bake, while the shrimp are added later so they stay tender instead of becoming rubbery.
Serve this gratin with a crisp salad, roasted vegetables, or warm garlic bread for a rich and satisfying seafood dinner.
Why You’ll Love This Creamy Garlic Shrimp & Potato Gratin
The combination of creamy potatoes and garlic butter shrimp makes this dish feel luxurious while still using familiar ingredients.
Thinly slicing the potatoes allows them to cook evenly and absorb plenty of flavor from the cream sauce.
The shrimp are added during the later stage of baking, which helps prevent overcooking.
Parmesan adds savory depth, while mozzarella creates a melty golden topping.
The whole casserole can also be customized with spinach, mushrooms, bacon, Cajun seasoning, or extra herbs.
Ingredients
For the Potatoes
- 2 pounds Yukon Gold or russet potatoes
- 1 tablespoon unsalted butter, for greasing
- 1 teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- ½ teaspoon garlic powder
For the Shrimp
- 1 pound large raw shrimp, peeled and deveined
- 1 tablespoon olive oil
- 1 tablespoon unsalted butter
- 3 garlic cloves, finely minced
- ½ teaspoon smoked paprika
- ½ teaspoon garlic powder
- ¼ teaspoon kosher salt
- ¼ teaspoon black pepper
- 1 tablespoon fresh lemon juice
For the Garlic Cream Sauce
- 3 tablespoons unsalted butter
- 5 garlic cloves, finely minced
- 3 tablespoons all-purpose flour
- 1½ cups whole milk
- 1½ cups heavy cream
- ½ cup low-sodium chicken or vegetable broth
- 1 teaspoon Dijon mustard
- 1 teaspoon Italian seasoning
- ½ teaspoon dried thyme
- ½ teaspoon onion powder
- ½ teaspoon kosher salt
- ¼ teaspoon freshly ground black pepper
- ¼ teaspoon red pepper flakes, optional
For the Cheese
- 1 cup freshly grated Parmesan cheese
- 1½ cups shredded mozzarella cheese
- ½ cup shredded Gruyère, cheddar, or Monterey Jack, optional
For Garnishing
- Fresh parsley
- Extra Parmesan
- Freshly cracked black pepper
- Lemon wedges
- Red pepper flakes, optional
How to Make Creamy Garlic Shrimp & Potato Gratin
1. Preheat the Oven
Preheat your oven to 375°F (190°C).
Butter a 9×13-inch baking dish generously.
2. Prepare the Potatoes
Peel the potatoes if desired.
Using a sharp knife or mandoline, slice them approximately ⅛ inch thick.
Keeping the slices similar in thickness is important so they cook at the same rate.
3. Season the Potatoes
Place the sliced potatoes in a large bowl.
Season with salt, black pepper, and garlic powder.
Toss gently.
4. Prepare the Shrimp
Pat the shrimp thoroughly dry with paper towels.
Season with smoked paprika, garlic powder, salt, and black pepper.
5. Sauté the Shrimp Briefly
Heat the olive oil and 1 tablespoon butter in a skillet over medium-high heat.
Add the shrimp in a single layer.
Cook for only about 45–60 seconds per side, just until they begin turning pink.
They should still be slightly undercooked in the center.
6. Add Garlic and Lemon
Add 3 minced garlic cloves.
Cook for approximately 20–30 seconds.
Add the lemon juice and immediately remove the skillet from the heat.
Transfer the shrimp to a plate.
Do not fully cook them yet because they will finish in the oven.
7. Start the Cream Sauce
Place a medium saucepan over medium-low heat.
Add 3 tablespoons butter.
Once melted, add the remaining 5 minced garlic cloves.
Cook for approximately 30–60 seconds, stirring constantly.
8. Add the Flour
Sprinkle in the flour.
Whisk continuously for approximately 1 minute.
This creates a light roux that will thicken the sauce.
9. Add the Milk
Slowly pour in the milk while whisking continuously.
Make sure there are no lumps.
10. Add the Cream and Broth
Pour in the heavy cream and broth.
Whisk until smooth.
11. Season the Sauce
Add Dijon mustard, Italian seasoning, thyme, onion powder, salt, black pepper, and red pepper flakes if using.
12. Simmer Gently
Cook over medium-low heat for approximately 4–6 minutes, stirring often.
The sauce should thicken enough to lightly coat the back of a spoon.
13. Add Parmesan
Reduce the heat to low.
Stir in ½ cup Parmesan.
Mix until melted and smooth.
Do not aggressively boil the sauce after adding cheese.
14. Create the First Potato Layer
Arrange approximately one-third of the potato slices in overlapping rows across the bottom of the baking dish.
15. Add Cream Sauce
Spoon approximately one-third of the garlic cream sauce evenly over the potatoes.
16. Add Cheese
Sprinkle with a little Parmesan and mozzarella.
17. Repeat the Layers
Add another layer of potatoes.
Top with more cream sauce and cheese.
Repeat until all the potatoes are used.
Reserve some sauce and most of the mozzarella for the final stages.
18. Cover the Gratin
Cover the baking dish tightly with foil.
Place it in the oven.
19. Bake the Potatoes
Bake covered for approximately 45–55 minutes.
The potatoes should begin becoming tender.
20. Check for Tenderness
Carefully insert a knife through the center.
It should enter the potatoes fairly easily but they do not need to be completely soft yet.
If they are still firm, cover and bake for another 10 minutes.
21. Add the Shrimp
Remove the foil.
Arrange the partially cooked shrimp over and slightly between the potatoes.
Pour any juices from the shrimp plate over the casserole.
22. Add Remaining Sauce
Spoon the remaining garlic cream sauce over the shrimp and potatoes.
23. Add the Cheese Topping
Sprinkle the remaining mozzarella and Parmesan evenly over the top.
Add Gruyère, cheddar, or Monterey Jack if using.
24. Bake Uncovered
Return the casserole to the oven.
Bake uncovered for approximately 12–18 minutes.
The shrimp should finish cooking, the potatoes should be completely tender, and the cheese should be bubbling.
Shrimp should reach 145°F (63°C).
25. Broil for Extra Browning
For a deeply golden top, broil for approximately 1–2 minutes.
Watch carefully.
26. Rest the Gratin
Remove the baking dish from the oven.
Let it rest for approximately 10–15 minutes.
This is important because the sauce thickens as it rests and the layers become easier to serve.
27. Garnish and Serve
Finish with fresh parsley, extra Parmesan, cracked black pepper, and red pepper flakes if desired.
Serve with fresh lemon wedges.
What to Serve With Creamy Garlic Shrimp & Potato Gratin
Because this dish is rich and filling, lighter sides work especially well.
Try:
- Arugula salad
- Caesar salad
- Cucumber tomato salad
- Roasted asparagus
- Green beans
- Broccoli
- Roasted zucchini
- Brussels sprouts
Warm garlic bread or crusty bread is also excellent for soaking up the creamy sauce.
Tips for the Best Shrimp & Potato Gratin
Slice the potatoes very thinly and evenly.
A mandoline makes this much easier.
Use Yukon Gold potatoes for a creamy texture or russets for a softer, starchier gratin.
Pat the shrimp completely dry.
Do not fully cook the shrimp before baking.
Keep the cheese sauce over gentle heat.
Use freshly grated Parmesan.
Cover the gratin during the first stage so the potatoes steam and soften.
Add the shrimp only near the end.
Always let the casserole rest before serving.
Easy Recipe Variations
Cajun Shrimp Potato Gratin
Season the shrimp with Cajun seasoning and add a pinch to the cream sauce.
Spinach Shrimp Gratin
Stir 2 cups fresh spinach into the cream sauce before layering.
Mushroom Garlic Shrimp Gratin
Sauté 8 ounces sliced mushrooms until golden and layer them with the potatoes.
Bacon Shrimp Potato Gratin
Add ½ cup crispy crumbled bacon between the potato layers.
Lobster and Shrimp Gratin
Replace half of the shrimp with chopped cooked lobster.
Garlic Parmesan Gratin
Increase the Parmesan to 1½ cups and omit the mozzarella for a more savory cheese profile.
Spicy Shrimp Gratin
Add cayenne, jalapeños, or extra red pepper flakes.
Broccoli Shrimp Gratin
Add small blanched broccoli florets when you add the shrimp.
How to Store Leftovers
Allow the gratin to cool before transferring leftovers to an airtight container.
Refrigerate for up to 2–3 days.
For the best texture, reheat individual portions in a 325°F (165°C) oven until hot throughout.
Cover loosely with foil during the first part of reheating so the potatoes do not dry out.
You can also microwave portions in short intervals, although the shrimp may become slightly firmer.
Freezing is not ideal because cream sauces can separate and potatoes may become grainy after thawing.
Frequently Asked Questions
Can I use frozen shrimp?
Yes.
Thaw them completely in the refrigerator and pat very dry before seasoning.
Can I use cooked shrimp?
Yes, but do not sauté them first.
Add cooked shrimp only during the final 5–8 minutes of baking so they do not become rubbery.
What potatoes are best?
Yukon Gold potatoes are excellent because they hold their shape while becoming creamy.
Russet potatoes also work and produce a softer gratin.
Why are my potatoes still hard?
The slices were likely too thick or needed additional covered baking time.
Cover the casserole and continue baking until a knife slides easily through the center.
Can I assemble the gratin ahead?
You can assemble the potato and cream layers several hours ahead and refrigerate.
For the best shrimp texture, add the shrimp only during the final baking stage.
Can I use half-and-half instead of heavy cream?
Yes.
The sauce will be lighter but still creamy.
Can I add more cheese?
Absolutely.
Gruyère, cheddar, Monterey Jack, mozzarella, and Parmesan all work well.
How do I know the shrimp are cooked?
They should be opaque, lightly curled, and reach 145°F (63°C).
Final Thoughts
This Creamy Garlic Shrimp & Potato Gratin combines tender layered potatoes, juicy shrimp, garlic, cream, Parmesan, mozzarella, herbs, and a golden bubbly cheese topping in one rich and comforting casserole.
The key is slicing the potatoes thinly, baking them until almost tender before adding the shrimp, and cooking the seafood only long enough to reach 145°F so it stays juicy.
Serve it with roasted vegetables or a crisp salad for an elegant seafood dinner that is creamy, garlicky, cheesy, and perfect for sharing.