Lay the chicken thighs out and sprinkle with salt and pepper, then dredge them in flour. Shake off the excess.Using a large and heavy pot, heat 3 tablespoons olive oil over medium high heat. Sear the chicken thighs, 4 at a time, just until brown on both sides, about 4 minutes per side. Transfer the thighs to a plate.
Add the other tablespoon of olive oil to the pot and sauté the mushrooms until they begin to brown, then add the onion, celery, pepper and carrot. Continue sautéing until the onion becomes translucent. Add the garlic and the sun dried tomatoes, if using. Sauté for one more minute.
Add the white wine. Simmer and reduce for about 2 minutes.
Now, this part is messy...but well worth it. Fish out the whole tomatoes from the can one at a time and crush them over the pot. I usually pull off any hard stem end of the tomato and discard that. Continue until you've crushed them all, then pour any of the juices left in the can into the pot as well.
Add the chicken stock, oregano, thyme leaves, capers and the chicken pieces. Reduce the heat to a low simmer, cover the pot and continue cooking for 40 to 45 minutes. Stir in the fresh basil just before serving. Serve with grated Parmesan.
This dish is perfect over whole wheat spaghetti or a soft polenta (recipe below).