Put onion, pepper slices and chopped garlic in the stock in a small saute pan and simmer for 10 minutes. Add shrimp and cook for 1 1/2 minutes on each side and remove from pan. Chop the tomatoes and add to pan along with wine and parsley. Simmerfor 10 minutes, stirring occasionally, then add the shrimp back for 1 minute stirring constantly. Serve hot over rice or linguine or with a nice crusty bread.