1. Preheat the oven to 275 degrees.
2. In a high sided skillet, or a dutch oven, heat a small amount of olive oil over high heat.
3. Season the thighs with salt and pepper on both sides.
4. Place the thighs in the pan, skin side down. Let the skin sear until brown, then flip and sear on the other side. Note: if you notice the skin sticking to the pan, just let the thigh continue to cook. It will pull away freely when it is ready.
5. Once seared on both sides, remove from the pan and reduce the heat to medium.
6. Add the guanciale and cook until the fat is rendered and the meat is a little crispy.
7. Remove the guanciale and strain off any excess fat, however leave enough fat to cover the bottom of the pan.
8. Add the onions and sauté until translucent.
9. Add the garlic, stir, and continue to cook for 3 minutes more.
10. Add the capers, olives, and guanciale, stir, and cook for another minute.
11. Carefully add all of the red wine at one time, and let cook until almost completely cooked out. Be sure to stir and scrape the bottom of the pan to release any cooked bits.
12. Once the wine is almost completely cooked out, add the tomatoes, stir and continue to cook for about 10 minutes.
13. Add the thighs to the tomato mixture, being sure to completely cover them in the sauce.
14. Cover with a tight fitting lid, or aluminum foil, and place in the oven.
15. Cook the thighs for 30 minutes. Once cooked, remove from the oven, and let rest for about 10 minutes before serving.

Note: While the thighs are braising in the oven, make a side dish to accompany them. I love this dish with cheesy polenta and a fresh simple green salad(like arugula with lemon and olive oil)