Fingerling Potatoes

Agata says:

Here is a lovely seafood entrée you can try when you want to impress. While there are a few cooking stages involved, it is not a complicated or difficult dish. You can make the “burro bianco” (better known as beurre blanc sauce in French) ahead and leave it at room temperature. You can also make the vegetable “ragu” ahead of time. This leaves only the fish for last-minute sauteeing.
This dish is so flexible, in fact, that you can omit the bed of vegetables and keep the butter sauce, or visa versa and still have an elegant dish that is quick and unfussy.
If you are aghast at the amount of butter in the sauce, keep in mind that you don’t have to use it all to nap your fish. If you choose to leave it out, the haunting presence of black trumpet mushrooms in the vegetable ragu gives the dish an enticing edge.

Halibut Fillet on Bed of Vegetables with “Burro Bianco” Sauce

Ingredients

For Vegetable Ragu:
¾ lb. small fingerling potatoes, halved
¼ cup A&V extra virgin olive oil
2 small carrots, cut into batons
5 small cipolline onions, peeled and halved
2 tbs. unsalted butter
1 leek (white part only), cleaned and chopped (should yield about ½ cup)
5 fresh sage leaves, julienned
1 oz. fresh black trumpet mushrooms, about 4-5 pieces, roughly chopped
salt and pepper to taste
For Burro Bianco Sauce:
1 tbs. Agata & Valentina extra virgin olive oil
1 large shallot, chopped
few branches fresh thyme
1 bay leaf
6-7 black peppercorns
1/3 cup white wine vinegar
½ lb (2 sticks) unsalted butter
For Fish:
4 halibut fillets (or small steaks), about 6 oz. each, (have fillets skinned)
pinch of salt and pepper
flour for dusting
4 tbs. canola oil + 2 tbs.unsalted butter

Directions

FOR RAGU:
Boil potatoes in salted water about 20 minutes, or until a fork pierces through easily.
Drain and set aside.
Heat a large skillet over medium heat for a minute and add olive oil. Add carrots and onions and cook about 10 minutes, stirring often, until caramelized. Add butter, then potatoes, leeks and sage and cook 1 minute more. Add black trumpet mushrooms and seasonings and cook 3 more minutes. Turn off heat and cover to keep warm.

FOR SAUCE:
Heat olive oil in small skillet over medium heat. Add shallot and thyme branches and cook for a minute. Add bay leaf, peppercorns and vinegar and let mixture cook until it reduces, about 3-4 minutes. Remove pot from heat and start whisking in butter, a little at time. When all butter is whisked in and mixture is thickened, strain and reserve.

FOR FISH:
Season fish lightly with salt and pepper and dust very lightly with flour. Heat oil and butter together in non-stick skillet over medium heat for a minute and cook 3-4 minutes on each side, about 7 minutes total, until top is lightly colored.
To plate, place vegetable ragu on bottom, top with fillet and nap with sauce. Serves 4