Baked Fish and Potatoes with Mustard Cream Sauce

Flaky baked cod and tender baby potatoes smothered in a creamy mustard sauce with capers and tons of fresh herbs. It sounds fancy, but I promise it’s not. The oven does all the work, and the mustard cream sauce gets mixed together in a bowl – you won’t even turn on the stove! 10 minutes of prep and you’re on to bigger and better things until dinner’s ready.

Cozy, creamy, and ready in under an hour.

• It’s the perfect transitional dinner – we’re moving out of the soups and stews season and into more fresh flavors. This baked fish really leans into that. Still warm and satisfying but topped with tons of fresh herbs and briny capers for a spring/summer flavor.
• It also bakes all in one dish, which means you can actually make it on a busy night! If you’re not a huge mustard fan, just use half or even a quarter of the amount of mustard. You’ll end up with a creamy sauce that has just a kiss of mustard flavor.
• If you are a mustard fanatic (like me), you are going to LOVE LOVE LOVE this mustard cream sauce. It’s creamy, bright, salty, and mustard-forward in the best possible way. I literally want to pour this mustard cream sauce over everything.

My personal serving recommendation?

Tear off bits of crusty sourdough loaf to sop up all the sauce and oil from the bottom of the pan. Serve with a crisp, chilled glass of white and relish in how easy this meal was to make and how delicious it tastes!

Here’s what you’ll need.

Remember: this is a blueprint.

• This is my favorite way to make this recipe but you can use it as a blueprint and make it your own!
• If you have a different type of fish – use that! Salmon would be delicious in this mustard cream sauce.
• If you have russets instead of baby gold potatoes, that’s great too.
• Any fresh, green herb will add fresh flavor.
• Make this recipe your own and use up what you’ve already got in the pantry.
• Don’t be afraid to experiment!

Here’s how it all comes together.

MIX SEASONING. Stir together olive oil, Old Bay seasoning, and rubbed sage with a couple big pinches of salt and pepper.

PREP + BAKE TATERS. Toss your baby gold potatoes in about 2/3 of the seasoned oil right in your baking dish, then roast for 20–25 minutes until just barely tender.

MAKE CREAM SAUCE. While the potatoes bake, whisk together the heavy cream, chicken broth, capers, garlic, both mustards, lemon juice, salt, and pepper.

ADD FISH. Push the potatoes to the sides of the baking dish, pat the cod dry, coat it in the remaining seasoned oil, and nestle it right into the center.

ADD SAUCE. Pour the mustard cream sauce over the cod and potatoes.

BAKE: Then pop it back in the oven and bake another 10–15 minutes until the cod flakes easily and the potatoes are fork-tender.

GARNISH + ENJOY. Finish with fresh parsley, chives, and a squeeze of lemon. Then dig in!

Things I learned while testing this recipe.

• Don’t skip the one-two punch of both mustards. The Dijon brings sharpness, and the stone-ground adds a little texture and depth. Together they’re so much better than either one alone.
• Baby gold potatoes roast up with the best creamy texture, but if you only have larger potatoes on hand, just cut them into 1”-1.5” chunks so they cook through in the same amount of time. Or halve or quarter your baby golden potatoes if they’re larger.
• You can use a large fillet of fish or small, individual portions of fish. The larger fillet will need to cook for a bit longer than multiple small fillets.
• The dish will seem pretty saucy when you start baking it, but the potatoes and fish will absorb the sauce beautifully as it cooks, and after it cools, giving you the perfect amount of mustard cream sauce in each bite!
• This is a mustard-forward dish. If you aren’t a huge mustard fan, cut it down to just 1 tablespoon of each (or less). You’ll end up with a creamy, delicious sauce with a hint of mustard.

The make-ahead meal you didn’t know you needed.

• The mustard cream sauce can be whisked together up to two days in advance and stored in the fridge.
• Just give it a good stir before pouring it over the fish.
• You can also par-bake the potatoes ahead of time, so when dinner rolls around, all you have to do is add the fish and sauce and pop it back in the oven.

Make it a meal.

• simple house salad
• crispy garlic bread
• sliced garlic cheese bread
• air fryer asparagus
• air fryer green beans

Just in case you have leftovers.

• STORAGE: Store leftovers in an airtight container in the refrigerator for up to 3 days. Keep the fish and potatoes together — the sauce only gets better as it sits.
• FREEZING: This dish isn’t ideal for freezing, as the cream sauce can separate, and the texture of the cod changes significantly once frozen and thawed. Best enjoyed fresh or within a few days.
• REHEATING: Reheat gently in a covered baking dish at 325 degrees for about 10–12 minutes or until warmed through.

More easy seafood recipes for your eating pleasure.