Cooking seafood at home is sometimes intimidating but poaching it is one of the easiest, fastest, and most forgiving ways to cook it. That is what I love about this poached flounder recipe! It is easy, flavorful, and fast.

Because you are cooking it submerged in liquid, the fish stays tender and flaky – and it absorbs all those delicious flavors you are cooking it in. 

For a light fish like flounder, sole, or trout, it is one of the simplest, most flavorful, and fastest ways to cook fish. 

Plus, it is one of the best ways to cook fish when you are cooking for just one or two!

What You Will Need

Poaching the fish and making the sauce are both easy and fast. While they do take two separate pans, everything comes together in about 20 minutes.

I put a pan of veggies and potatoes in the oven to roast while I made both and dinner was ready in no time

For the Poached Flounder

Flounder 

Flounder is a mild, light fish that is very thin and delicate. It is called a flat fish, and if you saw one at the fish counter, you’d see why. The fillets are very thin and can weigh between 3 – 6 oz each, but tend toward the lower end. 

If you have big eaters, you may need more than one fillet.

Vegetable Broth 

Any liquid, even water, will work, but I prefer something with some flavor like a well-seasoned vegetable broth. I usually make my own with leftover vegetables and store it in my freezer for things like this but you can also use packaged broth. I like both the College Inn and Pacific brands. 

You need just enough to submerge the fish in completely. I used a full 32 oz. carton of broth to cover 2 good-size fillets.

Onion 

While vegetable broth alone is just fine, I like some extra seasoning in my fish. Add a few sweet onion slices to the broth while it heats so the onion flavor has time to infuse into the broth. 

Lemon 

A few lemon slices do the same thing. Lemon and fish are just a classic combo and if you decide to make this without the lemon wine sauce, you’ll be happy you added these slices for the fish to pull in some lemon flavor. 

For the Sauce

Butter

Generally, I use butter only for baking, but once in a while, you need a little to make a really good cream sauce. I don’t use anywhere near what other recipes call for as I try to keep our intake low since we do try to follow the MIND diet principles at home, but this sauce needs a bit.  

Olive Oil 

To make up for the lower amount of butter in this recipe I add a hefty dose of E.V.O.O. It adds enough healthy fat to make the sauce silky smooth. 

Shallot 

Shallots have both a little onion and garlic flavor. They are smaller and more tender than an onion and don’t have the strong bite of garlic. That makes them perfect for a delicate sauce like this one. If you don’t have a shallot, mince a tablespoon of an onion and a garlic clove to replace it.  

White Wine 

While any white wine would work, a drier white wine is best in this sauce. Try a sauvignon blanc, pinot grigio, or chardonnay for the best results. You only need a little and the rest will be perfect to sip on with this meal. 

Lemon Juice

I used 2 full lemons for this recipe. ½ a lemon I cut into slices and put in with the fish while it poached and then I juiced the other 1 – ½ lemons and used the juice in the sauce. 

Plain Greek Yogurt

This is what gives this sauce its creamy texture. I used a low-fat plain Greek yogurt and whisked it into the sauce right before serving. 

Dill 

Lemon and dill are a classic combo for seafood! Mix the fresh dill in just before serving the sauce to get the maximum flavor! A few extra sprigs can be added to the poaching liquid for an infusion of dill flavor. 

How to Make it

Make the Sauce:

Step 1:

Heat the butter and oil in a frying pan. Add the shallot and cook it for 2 – 3 minutes, just until it is translucent.

Step 2: 

Add the wine and lemon juice and bring it to a boil. Cook it until it is reduced by about a half. This will take about 5 minutes. It will be a bit syrupy and thick.

Step 3: 

With a whisk or fork, add the yogurt and whisk it until the yogurt is dispersed and the sauce is creamy. Set it aside while you poach the fish.

Step 4: 

Place the vegetable broth, sliced onions, and lemon slices in a large saute pan. You want something wide enough to hold the fish fillet. Bring it to a boil.

Step 5:

Season the fish fillets with pepper. Then submerge them in the boiling liquid and let them cook for 2 – 5 minutes, depending on how thick your fillets are.

Watch my video for a step-by-step guide on how to poach fish.

Variations

While flounder is one of my favorite fish to poach, other fish that poach well include:

• Sole 
• Haddock 
• Trout
•  Cod  

You can use chicken broth or water in place of the vegetable broth. 

Storage Tips

Cooked fish will last in your fridge for 2 – 3 days. I suggest eating it within a day or two for the best flavor. You can reheat it gently in the microwave. Cook it on 50% power a minute at a time, checking for when it is hot.

You can freeze cooked fish, but the quality won’t be as good as when you first make it so it’s best to just buy what you need for one meal and enjoy it fresh from the poaching liquid.

The sauce will last in the fridge for a week. You will need to give it a good stir before using it as the yogurt may cause it to separate somewhat during storage. 

Other Recipes You Will Love

If you love seafood recipes here are some of my favorites! Check out my most recommended and 5 healthiest ways to prepare seafood at home for more ideas!

Greek Inspired Cod En Papillote – sounds fancy but is super easy and oh so delicious!

Grilled Shrimp with Pesto Pasta Salad – An easy summer seafood meal

If you try this and love it, please let me know in the comments below, and if you would add a rating that would be wonderful! Ratings help other people find these recipes so they can enjoy them too!