Boil the potatoes, peel and cut in wedges. Cut off both ends of zucchini and yellow squash, cut length wise in 4 equal parts. Remove most of the seeds by cutting the angle. Slice into 1/4-inch pieces. Blanch quickly in water and salt. Trim the fennel, cut in 2 lengthwise, sweat in olive oil, add lemon juice and fumet. Season with salt and pepper and braise for 5 minutes, covered. Add cherry tomatoes. Keep very al dente.
Brush a braising pan with butter. Place in it everything except half of the lemon juice and garnishes. Season the fish on both sides and add the fumet. Place the braising pan on a low flame until the liquid slightly simmers. Then place in a preheated 300 degree oven for 7 minutes. When cooked, place the fish with most of the vegetables into bowl, return the braising pan to the flame and finish with black olives lemon olive oil and lemon juice if necessary. Finish the dish by pouring the broth on the fish and garnish with chopped chives and chervil, serve immediately.
Recipe courtesy of The Castle at Tarrytown, NY