I’ve been making variations of this for over 12 years. I first made it in the hand-me-down oven our friends gave us to replace the one with the hole rusted in the side so we didn’t burn down our house. I churned out a lot of tasty meals from that old thing, and this fish was among our favorites.
I’ve upgraded my appliances since then, but I’m still making this fish. It’s one of the rare instances when I cook fish in the oven. Most of the time we’re all about the cast-iron skillet or the charcoal grill. Flounder is a little different. It’s very easy to cook, but it’s also very delicate. To keep those beautiful white fillets intact, I reach for a sheet pan. There’s no flipping, there’s less babysitting as it cooks, and one additional bonus for cooking fish in the oven: less lingering fishy smell after the kitchen’s clean.
You can pare down this recipe into a simple, healthy, “sheet-pan supper” because those are all the rage on Pinterest right now. Just put the miso-marinated fish and bok choy under the broiler, and in a few short minutes dinner is done. It’s delicious! Fish and bok choy are made for each other.
If I was only cooking this for myself, that’s what I would do. (But who am I kidding? I don’t cook more than an egg when I’m by myself.)
So I’m including one more element: a miso-coconut sauce spiked with kaffir lime. It brings everything together, transforming it into a Thai coconut curry of sorts.
You can be fancy and drizzle it lightly over the fish. But if it’s comfort food you’re after, add a big scoop of hot jasmine rice, ladle the sauce all over it, pour yourself some sake, and tuck in to this deliciousness. 
- 2 fillets flounder
- 5 cups chopped bok choy
- 1 tablespoon olive oil
- 1/4 cup red miso
- 1 tablespoon mirin
- 1 tablespoon sake
- 2 teaspoons coconut sugar
- 2 teaspoons lime juice
- 1 can coconut milk (not light)
- 3 green onions, sliced
- 4 kaffir lime leaves (or the zest of a lime)
- 2 tablespoons lime juice
- 1 tablespoon red miso
- 2 teaspoons minced fresh ginger
- 1-2 teaspoons minced jalapeño or Thai chiles, to taste
- 1/4 teaspoon salt
- hot jasmine rice
- sliced green onions, Thai basil, or cilantro
- Adjust the top rack of the oven to about 6 inches below the element. Preheat the broiler.
- Pat the fish dry and place it in a large shallow dish. Combine the marinade ingredients in a separate bowl and spread it over the fillets (reserve the remaining marinade). Refrigerate for 20-30 minutes.
- In a saucepan over medium-low heat, combine all the ingredients for the miso-coconut sauce. Simmer and reduce the liquid. Once it's reduced by about half, turn off the heat and put a lid on it.
- Dry the bok choy and toss it with the olive oil, then toss it with the remaining marinade. Spread it out on a baking sheet. Top with the fish fillets.
- Broil for 6-8 minutes, or until a skewer slips through the fish easily.
- Serve the fish and bok choy over jasmine rice, topped with coconut-miso sauce and a sprinkle of green onions or fresh herbs.
I devoted an entire garden bed to different types of bok choy this year, so get ready for more recipes with it!
ooh, this sounds (and looks) so yummy! I love Flounder and cooking it in the oven is a perfect way to keep that tender fish in tact. I’d like a big plate of this dish right now!
Thanks so much, Nicole! Flounder is a special treat around here.