Coat saute pan with olive oil, add garlic and shrimp and over medium heat cook until shrimp are halfway done. Turn shrimp and cook until almost done; add bell pepper, onion and cilantro and cook until shrimp are just done (a little on the rare side). Add tomatillo sauce, heat thoroughly. Put shrimp and sauce into a pewter dish. Serve dish on a dinner plate with lemon wedge as garnish.