Cook bacon in a medium nonstick skillet over medium heat until crisp. Remove bacon from pan; crumble. Reserve 1 tablespoon drippings in pan; increase heat to medium-high. Add bell pepper and garlic; sauté 3 minutes. Add green onions; sauté 1 minute. Remove from heat; stir in crumbled bacon and Swiss cheese. Divide the bacon mixture evenly among 6 (6-ounce) ramekins or custard cups coated with cooking spray.
Heat 2 cups milk in a saucepan over medium heat to 180° or until tiny bubbles form around the edge (do not boil). Place Parmigiano-Reggiano and the remaining ingredients in a large bowl; stir with a whisk. Gradually add the hot milk to egg mixture, stirring constantly with a whisk. Divide egg mixture evenly among ramekins. Place the ramekins in a roasting pan, and add hot water to pan to a depth of 1 inch. Bake at 350° for 32 minutes or until the center barely moves when the ramekin is touched. Remove ramekins from pan; let stand 10 minutes. Serve warm.