Heat the oven to 300℉.
Add the bacon to an extra large ovenproof dutch oven or pan (that has a lid-you'll need it later) and cook over medium heat until the bacon pieces are light brown.
Remove the bacon with a slotted spoon to a plate and set aside.
After patting the chicken with a paper towel to remove any excess moisture, liberally salt and pepper both sides of each piece of chicken.
Only if needed, add 1-2 Tablespoons of olive oil to brown the chicken. You can start with the bacon grease in the pan and add olive oil in if necessary.
In two to three batches, brown each side of each piece of chicken in the bacon fat (about 2 ½ minutes per side). As the chicken is browned, remove it from the pan and set aside on the plate with the bacon.
Add the onions, carrots, celery and herbes de Provence to the pan and cook over medium heat for about 10 minutes (until the onions are translucent).
Add the chopped garlic and the tomato paste and, while stirring, cook for another minute.
Add to the pot of vegetables the brandy, cooked bacon, chicken and any juices on the plate.
Tie the thyme and rosemary together with kitchen twine.
Add the thyme and rosemary bundle, bay leaves, wine and chicken stock to the pot and bring to a simmer over medium heat.
Once the stew starts to simmer, turn the flame off and cover the pot with the lid and place the pot in the oven for 45 minutes.
While the stew is cooking, mix the flour with 1 ½ Tablespoons butter together with a fork and set aside.
Melt the remaining 2 Tablespoons of butter over medium-low heat in a small sauté pan and cook the mushrooms for about 10 minutes until you start to see them brown. (This step can also be done while the stew is in the oven. Once the mushrooms are done, just set aside.)
Remove the stew from the oven and set on the stove. Add the flour/butter mixture and stir in. This will thicken the stew just a bit.
Add the sautéd mushrooms and pearl onions and bring the stew to a simmer and cook for 10 minutes.
Remove the thyme/rosemary bundle and bay leaves and garnish with the chopped parsley. Serve hot.