30-Minute Creamy Seafood Mac and Cheese

This creamy seafood mac and cheese comes together in one pot in 30 minutes, with tender shrimp, sweet lump crab, and a velvety cheese sauce that feels much fancier than it is. Weeknight indulgence at its easiest.

It is the kind of dish that gets requested every time I make it, and I keep a bag of frozen shrimp in the freezer just for this. No roux, no baking, just big comfort fast.

Why This Seafood Mac and Cheese Works

The sauce is the real star. Cream cheese melted right into the butter replaces a roux, so you get all that luscious body in half the time without a single lump.

Sharp cheddar gives it backbone, Parmesan adds salt and depth, and a pinch of Old Bay pulls the briny shrimp and sweet crab together into something that tastes like a coastal seafood shack did the cooking. It is rich without weighing you down, and it never turns out grainy if you keep the heat low.

Ingredients

• 8 oz elbow macaroni: any short, sturdy pasta works here
• 8 oz raw medium shrimp: peeled and deveined, tails removed
• 6 oz lump crab meat: picked over for shells
• 3 tbsp unsalted butter: divided
• 2 cloves garlic: minced fine
• 1 tsp Old Bay seasoning: plus more for serving
• 4 oz full-fat cream cheese: softened and cut into small cubes
• 1 ½ cups half-and-half
• 1 ½ cups sharp cheddar cheese: shredded off the block
• ¼ cup grated Parmesan
• Kosher salt and black pepper

Variations / Substitutions

• Swap shrimp for scallops or lobster: use the same weight of raw seafood and cook just until opaque, then chop into bite-sized pieces before folding in.
• Make it dairy-free: use unsweetened oat milk, vegan cream cheese, and meltable dairy-free cheddar; the sauce will be a touch thinner.
• Add a vegetable: fold in a handful of thawed frozen peas or lightly steamed broccoli florets at the end for color and crunch.
• Turn up the heat: a pinch of cayenne or a few splashes of hot sauce stirred into the sauce works beautifully against the richness.

If you like this one-pot seafood dinner, my Cajun Shrimp Pasta is another fast favorite.

How to Make Seafood Mac and Cheese

Step 1: Cook the Pasta

Bring a large pot of heavily salted water to a boil. Add the 8 oz elbow macaroni and cook 1 minute less than the package directs, about 7 to 8 minutes, until just al dente. The pasta will finish cooking in the sauce later, so pulling it a minute early keeps it from turning mushy. Drain and set aside.

Step 2: Sauté the Shrimp

Wipe out the same pot, return it to medium heat, and melt 1 tablespoon butter. Toss in the 8 oz shrimp in a single layer, season with half of the 1 tsp Old Bay, a pinch of salt, and a few cracks of pepper. Cook 2 minutes per side, just until pink and curled into loose C shapes. The shrimp should be barely done because they will warm through again when everything gets folded together. Transfer them to a plate and leave the pot off the heat for a moment.

Step 3: Build the Cheese Sauce

Drop the heat to low and add the remaining 2 tablespoons butter along with the minced garlic to the empty pot. Stir until the garlic is fragrant, about 30 seconds, then drop in the 4 oz cream cheese cubes. Pour in the 1 ½ cups half-and-half and whisk gently as the cream cheese melts into the liquid. You want the mixture steaming but never bubbling. Once it is smooth and warm, add the 1 ½ cups shredded cheddar and ¼ cup Parmesan a handful at a time, whisking after each addition until the cheese disappears into a silky sauce. Season with the rest of the Old Bay, a little salt, and pepper.

Step 4: Fold in the Crab and Pasta

Add the drained pasta and cooked shrimp back into the pot, then gently fold in the 6 oz lump crab meat, trying not to break up the lumps too much. Stir everything together with a rubber spatula until each piece of pasta is coated and the seafood is warmed through, about 1 minute. If the sauce looks too thick, splash in a tablespoon or two of milk.

Step 5: Spoon into Bowls

Ladle the mac and cheese into wide bowls while it is piping hot. Finish each serving with a light dusting of Old Bay and a scattering of fresh chopped parsley if you have it. The sauce will be glossy and loose at first and set up just slightly as it hits the bowl, so spoon it out right away.

Tips for the Creamiest Seafood Mac

• Shred the cheese yourself off a block. Pre-shredded cheese is coated with starch that can make the sauce turn grainy or separate.
• Keep the heat at low or medium-low once the cheese hits the pan. A hard simmer can break the sauce, and you lose all that smoothness.
• If your shrimp are cooked already (frozen or leftover), just skip the sauté step and fold them in at the very end so they warm without toughening.

Scale up for a crowd:

Storing Leftovers

• Refrigerate: Cool completely and store in an airtight container for up to 3 days. The sauce will thicken as it chills.
• Reheating: Warm gently in a saucepan over low heat with a splash of milk or half-and-half, stirring often, until the sauce loosens up and the seafood is heated through. Do not boil.

Frequently Asked Questions

Can I use other seafood?

Yes, small scallops or chopped lobster tail work well. Just cook any raw seafood until barely opaque before combining, since overdone seafood turns rubbery.

What if I do not have half-and-half?

Whole milk works, though the sauce will be a little thinner. Skip low-fat milk, it can curdle under the cheese.

Is there a gluten-free option?

Absolutely. Use your favorite GF elbow pasta and cook it just shy of al dente so it holds up in the sauce.

Can I make this ahead for a party?

You can assemble the whole dish, let it cool, then refrigerate up to 2 days. Reheat gently on the stove with a splash of milk, or transfer to a baking dish, top with buttered breadcrumbs, and warm in a 350°F oven for 15 to 20 minutes.

Seafood Mac and Cheese Recipe

Print Recipe Pin Recipe

Prep Time 10 minutes mins

Cook Time 20 minutes mins

Total Time 30 minutes mins

Servings: 4 servings

Calories: 680

Ingredients Method Notes

Ingredients

  

• 8 oz elbow macaroni
• 8 oz raw medium shrimp, peeled, deveined, tails removed
• 6 oz lump crab meat
• 3 tbsp unsalted butter, divided
• 2 cloves garlic, minced
• 1 tsp Old Bay seasoning, plus more for serving
• 4 oz full-fat cream cheese, softened
• 1 ½ cups half-and-half
• 1 ½ cups sharp cheddar cheese, shredded
• ¼ cup grated Parmesan
• Kosher salt and black pepper

Method

 

1. Cook pasta in salted boiling water 1 minute less than package directions. Drain and set aside.
2. In the same pot over medium heat, melt 1 tbsp butter. Add shrimp in a single layer, season with half the Old Bay, salt, and pepper. Cook 2 minutes per side until pink, then transfer to a plate.
3. Reduce heat to low. Melt remaining 2 tbsp butter in the pot, add garlic, and stir 30 seconds. Add cream cheese and half-and-half, whisking until smooth. Gradually add cheddar and Parmesan, whisking until melted. Season with remaining Old Bay, salt, and pepper.
4. Return pasta and shrimp to the pot, gently fold in crab meat, and stir until everything is hot and coated, about 1 minute. Add a splash of milk if needed.
5. Spoon into bowls immediately and top with a light dusting of Old Bay and parsley.

Notes

The sauce will thicken as it sits, so serve right away. When reheating leftovers, add a splash of milk or half-and-half and warm slowly on the stove. Lump crab meat sometimes has stray shell pieces; pick through it quickly before adding.