In a shallow dish, mix together flour and paprika as well as salt and pepper. Remove chicken skin if still on the pieces. Season chicken with salt and pepper. Dredge the chicken pieces in the flour and shake off the excess.
In a large frying pan add a couple of Tbsp of oil and heat until very hot. Add chicken pieces, without overcrowding them, and brown on all sides. Move to a plate and brown remaining pieces.
In a large dutch oven or large heavy duty pot cook the bacon over medium heat until the bacon releases some of the fat and it is about halfway cooked. Add the onion and saute until onion is translucent, about 5 minutes. Stir in the mushrooms and sprinkle a bit of salt on top, and saute until mushrooms release some of their moisture. Stir in bell peppers and garlic. Cook until fragrant, about 1 minute. Add the tarragon and wine, using wine to deglaze the pan, and cook until wine reduces by half, 5-7 minutes. Add the reserved chicken stock just until the chicken is almost covered (amount will vary). Bring to a boil, then reduce heat and simmer low, partially covered, until chicken is almost cooked through, about 35-40 minutes.
Over the low heat, if the sauce seems very thin you can add a thickener (slurry) at this point and bring to a boil to thicken. Stir in heavy cream, mustard and spinach , and simmer another 15 minutes until chicken is completely cooked through and the sauce thickens. Taste for salt and pepper.
Serve chicken topped with the sauce.
Enjoy!