In a large saute pan, heat the oil over medium-high heat. When the oil is hot, add the rabbit and cook until brown. Turn the rabbit over and cook the other side. Remove the browned rabbit to a plate and hold aside.
When all rabbit is removed, add the onion, garlic, and mushrooms. Saute until the onion is tender. Add in the browned rabbit and season with salt, pepper and red pepper flakes. Add the tomatoes, cover, and simmer for 30 minutes, or until rabbit is done. Remove the rabbit from the sauce and keep warm. Remove the cover and simmer for another 10 minutes on high heat to concentrate the sauce. Adjust the seasoning if necessary. Pour sauce on top of rabbit and sprinkle with parsley.