Pat chicken dry with paper towels and season generously with salt and pepper.
In a large, heavy bottomed Dutch oven, cook bacon over medium high heat for 8 - 10 minutes, until lightly browned, then remove and set aside.
In batches, sear the chicken in the bacon fat in a single layer, turning to brown evenly. Remove chicken and set aside. Discard excess fat from pan.
Add 2 tablespoons butter to the pan and over medium high heat, stir in the mushrooms. Cook for 10-12 minutes, without stirring much. Stir in the pearl onions and sauté for about 5 minutes, until lightly browned. Remove mushrooms and pearl onions from pan and set aside.
Stir in the sliced onions. Sauté for about 5 minutes. Add the garlic, thyme, and bay leaves and stir to mix.
Add the white wine and chicken stock and bring to a light boil.
Place the chicken back in the pot in a single layer, the liquid should not cover the chicken. Sprinkle bacon over chicken, cover and transfer to the oven for 30 minutes.
Remove pot from the oven and add the mushrooms, pearl onions, and lemon juice and return to the oven, covered, for 1 to 1 1/2 hours, or until chicken seems very tender.
Remove the pot from the oven and place on stove top. Remove the chicken pieces to a platter and bring the pot to a boil. Continue to cook until the mixture reduces by three-fourths and becomes fairly thick and saucy. Lower the heat, and return chicken to the pot to heat through. Taste and adjust the seasoning if necessary.
Garnish with parsley and serve over a bed of creamy polenta, or mashed potatoes, or roasted baby potatoes.
Notes
To make ahead, prepare dish all the way without adding the lemon juice and parsley. Can be made up to two days. Reheat in a 300 degree oven for 30 minutes or on stove top, over low heat, until heated through.