Preheat oven to 350 degrees F.
Cut the endives in half, remove the core, place in a small pot. Add 1 tablespoon butter, salt, pepper, sugar, and 1 cup ale beer. Bring to a boil, cover with a piece of parchment paper and place in a 350 degree oven. Cook for 30 to 40 minutes, until slightly brown in color and the beer has reduced by 1/2.
Meanwhile, heat the oil in an ovenproof frying pan or casserole. Season the meat with salt and pepper on all sides. When the oil is very hot, sear the meat, caramelizing all sides evenly. When seared, drain off the fat and add the Belgian beer.
Increase the oven temperature to 450 degrees F.
Roast the meat in the oven for 15 to 20 minutes. Remove the pan from the oven and let the meat rest for 5 minutes before slicing.
Melt 2 tablespoons butter in a heavy-bottomed pot, add the onions, and cook for 3 to 4 minutes. Squeeze the mushrooms out of the juice, and add to the onions, cook for another 2 to 3 minutes. Deglaze the pan with 2 cups beer, and reduce until almost dry. Then add the mushroom rehydrating liquid, and reduce until almost dry. Add the veal stock and the cream, and reduce at low heat until thick. Check the seasoning, reserve.
To serve, slice the meat in 1/2 to 1/4-inch thick pieces. Place on a plate, surround with the endive leaves. Put the wild mushrooms around the meat and cover with a thin layer of the sauce and serve immediately.