Pre-heat oven to 350. Brown the chicken in the oil in a skillet. Do it in two batches if necessary, and transfer the chicken to an oven safe casserole.
2 lbs chicken, 2 Tablespoon oil
Saute the onions and mushrooms in the same skillet for a few minutes, then add to the chicken.
24 small pearl onions, 12 oz mushrooms
Deglaze the skillet with a can of mushroom soup. Pour it over the meat in the casserole and add 1/2 c. of vermouth.