Asparagus-Zucchini Frittata

12 ounces fresh asparagus or one 9- or 10-ounce package frozen cut asparagus

2 tablespoons all-purpose flour

3/4 teaspoon salt

1/4 cup chopped bottled roasted red sweet pepper s, drained

Nonstick cooking spray

3 to 4 tablespoons finely shredded Parmesan cheese

1/4 to 1/2 teaspoon ground black pepper

1 small yellow sweet pepper , cut into 1/4-inch-wide strips

1/2 cup shredded reduced-fat mozzarella cheese (2 ounces)

1 tablespoon snipped fresh dill or 1 teaspoon dried dillweed

Fresh dill sprigs

1/2 of a small zucchini , halved lengthwise and cut into 1/4-inch-thick slices (about 1/2 cup)

2 cups refrigerated or frozen egg product, thawed, or 8 eggs

1/3 cup chopped onion