Ham & Spinach Pasta

This might have been a recipezaar recipe - I forgot to note where I got it in my files. Don really liked this one - he's a pasta-lover. I liked the spinach in it, and think that it needs more ham.

8 ounces dried mostaccioli pasta or ziti pasta or elbow macaroni (I used Dreamfields)
3 tablespoons margarine
3 medium onions, cut into thin wedges (about 3 cups) or 5 medium leeks, sliced (about 3 cups)
2 garlic cloves, minced
¼ cup all-purpose flour
½ teaspoon dried thyme, crushed
⅛ teaspoon pepper
1 ½ cups half-and-half or light cream or milk
1 ½ cups chicken broth
1 ½ cups cooked ham, cubed
1 (10 ounce) package frozen chopped spinach, thawed and drained

1. Cook pasta according to package. Drain and rinse.
2. In large saucepan melt margarine. Add onion or leeks and garlic. Cover and cook about 5 mins or till onions are tender, stirring occasionally.
3. Stir in flour, thyme, and pepper.
4. Add half and half, light cream, or milk and the chicken broth all at once.
5. Cook and stir til thick and bubbly. Cook and stir for 1 minute more.
6. Stir in pasta, ham, and spinach.
7. Spoon mixture into a 3 quart casserole.
8. Cover and bake 30-35 mins at 350 or until heated through. Let stand 5 minutes. Stir gently before serving.

This is for Ruth's Presto Pasta Night!