In a large Dutch oven, crisp the bacon over medium heat for 8-10 minutes. Transfer the bacon bits to a plate and leave about 2 tablespoons of bacon grease in the pot.
Season chicken thighs with salt and black pepper.
Put the thighs on the pot. Cook on medium-high heat for 4 minutes on each side or until golden brown and crispy. Transfer the browned chicken thighs to a plate.
Add onion, and celery to the pot. Stir for 8 minutes over medium heat. Add the garlic and thyme. Continue stirring for 2 minutes or until the vegetables are soft but not browned.
Add flour and stir for 1-2 minutes. Add paprika and stir for a few seconds.
Add beer and let the foam subside for about 1-2 minutes. Add the diced tomatoes and stock. Let it simmer for a few minutes until the sauce is slightly thickened.
Put the browned chicken (including the juice) back into the pot, skin side up.
Simmer, uncovered, for 40 minutes over medium-low heat or longer, until the chicken is fully cooked and the sauce reaches your desired consistency and taste. Stirring and gently scrape the bottom of the pan occasionally to avoid burning.
10 minutes before the cooking process is done, add bacon and saffron. Stir to combine. Taste and adjust with extra salt and black pepper if needed.
Serve with chopped parsley, noodles, or mashed potatoes.