Broccoli and Pasta Casseroles

slices whole-wheat bread (1 ounce)

head broccoli (1 pound), cut into florets, stems peeled and cut into 1/2-inch pieces

whole-wheat fusilli pasta

plus 1 teaspoon extra-virgin olive oil

medium onion (5 ounces), finely chopped (about 1 cup)

plus 1 1/2 teaspoons all-purpose flour

ground mustard

skim milk

part-skim ricotta cheese, pureed

grated Parmesan cheese (1 cup)

Coarse salt and freshly ground pepper