Remove guts and gills from fish and rinse out cavity.

[You can get your fishmonger to do this if purchasing at the store.]

Light a good sized fire in the wood stove and let it burn down to glowing embers.

Sprinkle the inside and outside with kosher salt and pepper. 

Stuff the cavity with sliced fennel bulb, fronds, 3 thinly sliced rounds of lemon, a couple of small pats of butter, and a few sprigs of watercress if using. 

Lay out a piece of foil several inches longer on each side than the fish. Rub the foil where the fish will lay with a piece of butter.

Place stuffed fish in the middle of the foil. Top with a couple of dabs of butter and a sprinkling of fennel fronds. 

Place another piece of foil the same size over the fish. 

Tightly wrap the edges, creating a seal by which nothing can leak out. 

If you are using particularly inexpensive thin foil, you may want to double up.

Place the foil wrapped fish on top of the embers in the wood stove and close the door. If doing this in the fireplace, keep the fish towards the back to catch radiant heat from the fireplace walls. 

Cook for approximately 10 minutes, then carefully flip, using tongs or heat proof gloves, and cook for another 10 minutes. 

Since the size of fish, heat from the embers, and thickness of foil are all variables, there is no way of telling you when the fish will be cooked to perfection. You’ll have to use some intuition here. 

Take the fish out of the wood stove and carefully open the foil, keeping clear of the hand and face burning steam. 

Use a fork to try flaking off some of the meat in the middle of the fish. If it flakes off easily, the fish is cooked. If not, it may need to go back in for a little while longer. 

Meanwhile, put the lemon juice and chopped garlic in a pot. Gently heat it up, letting the hot lemon juice soften the garlic, about 5 minutes. 

Dump the garlic/lemon juice in a bowl and set aside. Put the butter in the pot (don’t worry about rinsing it out) and heat over medium high.

Cook the butter, swirling often, until the milk solids begin to turn brown and everything starts smelling toasty and nutty. 

Add the capers, chilies (if using), and the garlic/lemon to the brown butter and give it a good stir. Keep warm. 

Tear the lettuce(s) by hand and create a bed of it on a large (oval if possible) plate.

Scatter sliced fennel, onion, and pickled mushrooms on top. 

Unwrap the fish and carefully transfer it on top of the bed of lettuce. Drizzle any juices in the tinfoil over the lettuce. 

Pour the butter sauce over the fish, saving a small amount to drizzle over the salad. 

Scatter a couple of fresh fennel fronds on top. 

Serve whole, with diners eating fish and salad right from the serving plate. Be mindful of bones. 

Once the meat from one side is eaten, try to carefully lift the whole skeleton up in one go, which will provide you with a boneless filet on the bottom!

Enjoy!