Heat a large skillet over high heat and add the canola oil.
Arrange the chicken pieces in a single layer on a baking sheet, and season them with salt and red pepper flakes. Turn the pieces over and season on the other side.
When the oil begins to smoke lightly, reduce the heat to medium. Use a pair of metal tongs to carefully add the chicken, skin side down, to the skillet. Do not overcrowd the pan.
Sautée, resisting the temptation to move or turn the pieces until they have browned on the first side, 5 to 8 minutes. Turn the chicken pieces over and brown on that side, 5 to 8 minutes. Transfer the chicken pieces to a rimmed baking sheet and set aside.
To make the sauce add the onions and a pinch of salt to the skillet you browned the chicken in, and cook until the onions become translucent, 3 to 5 minutes. Add garlic and mushrooms and cook over medium heat, until the vegetables turn light brown, 10 to 12 minutes.
Add the white wine, season with salt, and simmer until almost all of the liquid is gone, 5 to 8 minutes (Cooking the wine out first is important so that there won’t be any raw alcohol flavor in the sauce.) Add the tomatoes with their juices and bring to a simmer. Add the bay leaves and thyme sprigs.
Arrange the chicken pieces in a single layer in the pan and pour any accumulated juices into the sauce as well. Simmer over low heat until the chicken is cooked through, 40 to 50 minutes. Use a wooden spoon to break up some of the tomatoes.
Remove the pan from the heat and add the rosemary. Allow the chicken to rest on the stove, off the heat, for about 10 minutes and then remove and discard the rosemary sprig, thyme sprig, and bay leaves. Taste for seasoning and serve.