Cajun Salmon and Shrimp with Creamy Mashed Potatoes – Spicy, Buttery, Restaurant-Style Dinner

This Cajun Salmon & Shrimp with Creamy Mashed Potatoes is that “fancy restaurant plate” you can actually make in your own kitchen. You get flaky salmon, juicy shrimp, and a buttery Cajun pan sauce spooned over ultra-creamy mashed potatoes.

It’s bold and spicy from the Cajun seasoning, rich from the butter and garlic, and balanced by soft mashed potatoes that soak up every drop.

Below you’ll see how to pan-sear the salmon without drying it out, how to keep the shrimp tender (not rubbery), how to build a quick pan sauce, and how to get mashed potatoes that are creamy and smooth.

Why You’ll Love This Cajun Salmon & Shrimp

Full steakhouse/seafood restaurant energy at home.
Creamy + spicy combo – smooth mashed potatoes under smoky Cajun butter sauce.
One pan for the seafood – fast cleanup.
Flexible heat level – you control the spice.
Date night plate / Sunday dinner plate / I deserve this plate.

Ingredients

For the Cajun Salmon & Shrimp

2 salmon fillets (about 5–6 oz each), skin on or off
8–10 large shrimp, peeled and deveined
1–2 tablespoons Cajun seasoning (store-bought or homemade)
1 tablespoon olive oil
2 tablespoons butter
2 cloves garlic, minced
1/2 cup heavy cream or half-and-half (for a richer pan sauce, optional but amazing)
Splash of chicken broth or seafood broth (just to loosen the sauce if needed)
Salt and black pepper, to taste
Squeeze of fresh lemon, to finish
Optional: pinch of smoked paprika or cayenne for extra heat
Optional garnish: chopped parsley or chives

For the Creamy Mashed Potatoes

2 pounds (about 900 g) Yukon Gold potatoes, peeled and cut into chunks
6 tablespoons unsalted butter
1/2 cup heavy cream or half-and-half, warmed
1 head roasted garlic or 3–4 cloves garlic gently cooked in butter, mashed
Salt and black pepper, to taste
Optional: 2 tablespoons sour cream or cream cheese for extra richness
Optional garnish: chives

How to Make Cajun Salmon & Shrimp with Creamy Mashed Potatoes

1. Make the mashed potatoes

Add peeled potato chunks to a large pot. Cover with cold water and about 1 teaspoon salt. Bring to a boil, then reduce to a gentle boil and cook until potatoes are very tender, about 15–20 minutes.

Drain well. Let them sit in the hot pot 1–2 minutes so extra steam escapes.

In a small saucepan, melt the butter with the roasted garlic (or softened garlic cloves) over low heat. Add the warm cream and stir.

Mash the potatoes (or use a potato ricer for extra smooth). Pour in the warm garlic butter/cream mixture and mash until creamy. Add sour cream/cream cheese if using. Taste and season with salt and pepper.

Cover and keep warm on very low heat or cover and set aside.

Tip: Warm dairy blends in smoothly. Cold milk can make potatoes gummy.

2. Season the seafood

Pat the salmon dry with a paper towel. Pat the shrimp dry too.

Season both with Cajun seasoning, plus a little salt and black pepper. (If your Cajun seasoning is salty, go easy on extra salt.)

You can also sprinkle on a pinch of smoked paprika or cayenne if you want more heat.

3. Sear the salmon

Heat olive oil in a skillet over medium to medium-high.

Place salmon in the pan (skin-side down first if it has skin). Cook until the first side is golden and mostly cooked through, then flip and cook the other side until just opaque in the center. Time depends on thickness, usually about 3–4 minutes per side.

Remove the salmon to a plate. Tent loosely so it stays warm.

Tip: Don’t overcook. Salmon should still be juicy and just slightly translucent in the very center.

4. Cook the shrimp

In the same skillet, add butter. When it melts, add the shrimp.

Cook the shrimp 1–2 minutes per side, just until pink and opaque. Add minced garlic in the last minute so it softens and perfumes the butter but doesn’t burn.

Remove shrimp and set aside with the salmon.

5. Make the Cajun pan sauce

Still using that same skillet (with all the browned bits and butter), lower heat to medium-low.

Splash in a little chicken broth or seafood broth and scrape up the browned bits.

Pour in the heavy cream or half-and-half and stir. Add a pinch more Cajun seasoning if you want a stronger kick. Let it gently simmer for 1–2 minutes to thicken slightly.

Finish with a squeeze of fresh lemon to brighten the sauce.

Taste and adjust: more salt? more pepper? more heat?

You just made the sauce that’s going over the salmon, shrimp, and potatoes.

6. Plate it

Spoon a generous bed of creamy mashed potatoes onto the plate.

Top with the Cajun salmon fillet and a few shrimp.

Drizzle the warm Cajun butter cream sauce over the top.

Garnish with chopped parsley or chives and a crack of black pepper.

Serve right away while everything is hot and glossy.

Serving Suggestions for Cajun Salmon & Shrimp

This plate is already rich, so keep sides light and fresh:

Steamed or roasted asparagus
Garlicky green beans
Sautéed spinach with lemon
Simple side salad with a citrus vinaigrette

If you’re going full comfort mode, you can also serve buttered corn or roasted broccoli.

You can also build it “bowl style”: mashed potatoes in a shallow bowl, salmon broken into big chunks, shrimp on top, sauce over everything. Spoon optional.

Cook’s Tips

Dry the protein first.
Patting salmon and shrimp dry helps you get color. Moisture = steam, not sear.

Watch shrimp timing.
Shrimp go from perfect to rubbery really fast. As soon as they turn pink and curl slightly, they’re done.

Control your Cajun spice level.
Store-bought Cajun seasoning can be mild or HOT. Taste yours and adjust. You can always add heat at the end with cayenne.

Don’t skip the lemon.
That tiny squeeze of lemon at the end wakes up the sauce and keeps it from tasting too heavy.

Yukon Gold potatoes = silky.
They’re naturally buttery and make super creamy mash without tasting mealy.

Variations & Add-Ins

Blackened style:
Sear the salmon and shrimp on slightly higher heat with extra Cajun seasoning to get a darker crust.
Add veggies to the sauce:
Sauté finely diced onion or bell pepper in the butter before adding shrimp for more sweetness and color.
Herb finish:
Stir fresh chopped parsley, chives, or green onion into the mashed potatoes for a steakhouse-style side.
Lighter sauce:
Skip the heavy cream and just finish the pan with broth, garlic, lemon, and a tablespoon of butter for a lighter, more “garlic butter Cajun” style.

Storage & Reheating

Fridge:
Store leftovers in airtight containers up to 2–3 days.

Keep components separate if you can:

Mashed potatoes in one container
Salmon/shrimp in another
Sauce in another

Reheat:

Mashed potatoes: Warm low and slow with a splash of cream or milk.
Salmon & shrimp: Warm gently on low heat in a covered pan or in short microwave bursts — don’t overcook or seafood gets tough.
Sauce: Rewarm on low and whisk. Add a spoon of cream or broth if it thickened too much in the fridge.

Freezer:
Mashed potatoes freeze decently because of the butter/cream. Cooked shrimp and salmon can freeze, but texture is best fresh. This dish is best enjoyed same day or next day.

FAQ

Is this really spicy?
It’s as spicy as your Cajun seasoning. Some blends are smoky and mild, some are hot. You’re in control.

Can I make this without cream?
Yes. You can do a simple lemon-garlic butter pan sauce instead: butter + garlic + splash broth + squeeze lemon.

Can I use frozen shrimp?
Absolutely. Thaw completely, pat dry very well, then season and cook.

What if I don’t like salmon?
You can swap with another fish like cod or tilapia — just pan-sear gently and don’t overcook. Chicken breast or thighs (sliced) also work with the same Cajun butter sauce.

Can I use instant mashed potatoes?
If you’re in a rush, yes. Stir in butter, garlic, and a splash of cream so they taste richer and feel more “homemade.”

Cajun Salmon & Shrimp with Creamy Mashed Potatoes is pure comfort: spicy, buttery seafood on top of soft, garlicky potatoes with a warm Cajun cream sauce poured over everything. It’s the kind of plate that feels special without needing a restaurant, and it looks impressive when you serve it.

Make it for a cozy at-home dinner, a date night, or a “treat yourself” Sunday meal. Once you try that sauce over the potatoes, you’ll start putting it on everything.