Heat olive oil in a large skillet and saute onion and celery a couple of minutes. Stir in artichokes, breaking up with spatula and add more olive oil if needed, and saute until edges start to turn brown. Season with salt & pepper. Add garlic and saute a little. Pour into a small dutch oven. Add tomatoes & mushrooms and the rest of the seasonings except parsley and parmesan. Simmer uncovered about 30 minutes until thick. Adjust seasonings to taste. Cover and let sit a while. Before serving, heat and stir in parsley. Serve over pasta sprinkled with parmesan cheese.