In a saucepan, bring about 1 inch water to boiling. Add asparagus, pepper strips, and onion; bring just to boiling. Reduce heat slightly; cover and boil about 1 minute or until crisp-tender. Drain well, reserving some asparagus tips for garnish. Spread asparagus-pepper mixture evenly in baking dish. Layer zucchini slices over.
Combine eggs, half-and-half, parsley, salt, and pepper. Pour over vegetables in baking dish. Bake, uncovered, in a 350 degree F oven about 35 minutes or until a knife inserted near center comes out clean. Let stand 10 minutes before serving. Garnish each serving with asparagus tips, if desired. Makes 8 servings.