Burgundian Eel Stew in Red Wine

Pat the eel sections thoroughly dry with paper towel and season generously with salt and pepper. Mince the garlic, dice the onions, shallots, carrots and celery, quarter the mushrooms, and measure out all remaining ingredients.

Place the eel sections in a bowl with the red wine, cognac, diced onions, shallots, garlic, carrots, celery, bouquet garni and crushed peppercorns. Cover and refrigerate for 12 hours.

Lift the eel from the marinade and pat dry. Strain the marinade through a fine sieve, reserving both the liquid and the vegetables separately. Set a large wide saucepan over medium-high heat, add 1 tablespoon butter and the lardons and cook until the fat renders and the lardons turn golden, about 5 minutes.

Remove the lardons with a slotted spoon and set aside. In the same pan over medium-high heat, sear the eel sections in batches until browned on all sides, about 3 minutes per batch, then transfer to a plate.

Reduce the heat to medium, add 1 tablespoon butter to the pan and cook the reserved marinade vegetables, stirring occasionally, until softened and lightly golden, about 8 minutes.

Sprinkle the 1 tablespoon flour over the vegetables and stir constantly for 2 minutes until the raw flour smell disappears and the roux turns a light nut-brown colour.

Pour in the reserved marinade liquid and fish stock, scraping up all the browned bits from the base of the pan, then bring to a vigorous boil. Skim any foam from the surface.

Return the eel and lardons to the pan, reduce the heat to low, partially cover and braise gently until the eel is fully cooked through and reads 63°C on a meat thermometer inserted into the thickest section, about 25 minutes.

Meanwhile, melt the remaining 1 tablespoon butter in a small frying pan over medium heat, add the pearl onions and sugar and cook, shaking the pan regularly, until the onions are glazed and deep golden, about 12 minutes. Set aside.

Lift the eel sections carefully from the braising liquid onto a warm plate and tent with foil. Strain the braising liquid through a fine sieve into a clean saucepan, pressing on the solids; discard the solids and bouquet garni.

Bring the strained sauce to a brisk simmer over medium-high heat and reduce by one-third, about 10 minutes, until noticeably thickened.

Work the softened 1 tablespoon butter together with the 1 tablespoon flour with a fork until a smooth paste forms for the beurre manié. Whisk this paste into the simmering sauce a little at a time until the sauce is glossy and coats the back of a spoon.

Return the eel and glazed pearl onions to the sauce, add the quartered mushrooms and simmer gently for 5 minutes to warm everything through and cook the mushrooms.

While the final simmer runs, fry the sourdough triangles in a little butter in a small pan over medium-high heat until golden and crisp on both sides, about 2 minutes per side.

Divide the matelote among four warmed shallow bowls, arrange the croûton triangles around the edge and finish with a scatter of flat-leaf parsley.