Cook pasta according to package directions. In a nonstick skillet, saute onion in oil for 1-1/2 minutes. Add garlic; cook 30 seconds longer. Add the sweet peppers; cook and stir for 2-3 minutes or until vegetables are tender. Stir in the olives, oregano, salt and cayenne. Add water; cook and stir until mixture comes to a boil. Drain pasta and stir into skillet. Remove from the heat. Stir in cheese. Serve immediately.