flounder fillets rolled around a mushroom and roasted-greens filling, baked on a bed of seasonal root vegetables

This dinner takes real time: 3 separate root vegetables, each with their greens still attached, a filling that needs its own pan, and a delicate fillet you have to roll carefully so it does not fall apart in the oven. Plan for real time at the cutting board before you start this one. What lands on the plate at the end earns every minute of that effort.

Buy the flounder fresh, ask the fish counter which catch came in most recently, and cook it that same day if you can manage it. A little curiosity about where a fish came from changes how you handle it in the kitchen.

Selenium is the reason a mild fish like this earns a regular spot on your plate, a mineral tied closely to proper thyroid hormone conversion and to keeping the gland's own antioxidant systems steady, worth real attention when an Autoimmune thyroid diagnosis is somewhere in your history, since the thyroid runs on very little of it and notices a shortage fast. Beta-carotene from the carrots and beets works the same way, an early building block for vitamin A that supports the gut's mucosal lining. Chop every green in the bunch into the filling. None of it belongs in the compost.

Ingredients

• About 4 flounder fillets (quantity not stated in the original source - plan on 1 fillet per serving; sole or other flat white fish may be substituted)
• 1 bunch beets with greens
• 1 bunch radishes with greens
• 1 bunch carrots with greens
• 1/4 pound Brussels sprouts
• 3 tablespoons olive oil, divided
• Salt
• 1 large shallot, finely chopped
• 1/2 pound fresh mushrooms, diced
• 1/2 teaspoon dried oregano
• 1/2 lemon, cut into paper-thin slices

Method

Preheat the oven to 200C/400F.

Separate the greens from the beet, radish, and carrot roots. Set the greens aside. Scrub the beets and carrots and cut them into roughly equal pieces so they will cook in the same time. Trim the radishes and halve or quarter any large ones. Halve the Brussels sprouts through the stem.

Toss all the root vegetables and Brussels sprouts with 2 tablespoons of the olive oil and a good pinch of salt. Spread them in a single layer on a large roasting tray. Roast for 25 to 30 minutes, turning once halfway, until tender and beginning to colour at the edges.

While the vegetables roast, prepare the filling. Wash and roughly chop the beet greens, radish greens, and carrot greens - all of them go into the filling. Warm the remaining 1 tablespoon of olive oil in a wide skillet over medium heat. Add the shallot and cook for about 3 minutes until soft. Add the diced mushrooms and cook, stirring occasionally, until all their moisture has evaporated and they begin to colour, about 5 to 6 minutes. Add the chopped greens, season with the dried oregano and a pinch of salt, and cook until wilted and any remaining moisture has cooked off, about 2 to 3 minutes. Remove from the heat.

Lay the flounder fillets flat on a clean work surface. Season each fillet lightly with salt. Spoon a line of the mushroom-greens filling across the centre of each fillet, then roll the fillet around the filling. Secure with a toothpick if needed to keep the roll together.

Remove the roasting tray from the oven. Nestle the rolled flounder pieces directly on the bed of roasted vegetables. Lay the thin lemon slices over the top of each rolled fillet. Return the tray to the oven and bake for 15 to 18 minutes, until the fish is opaque all the way through and flakes easily when tested with a fork.

Remove the toothpicks. Serve directly from the tray.

Air fryer variation

The roasted root vegetables can be prepared in an air fryer at 200C/390F for 15 to 18 minutes, shaking the basket halfway, if you want to free up the oven. Cook the stuffed flounder rolls in the oven as above - the fish is too delicate and the filling too uneven in shape to air fry reliably.

*Adapted from gutsybynature.com (Jaime Hartman)*