Step 1

1 Preheat oven to 350u02daF.

Step 2

2 Cook pasta for 3 minutes and drain well.

Step 3

3 In medium saucepan, melt butter. Stir in flour, mustard, salt, and pepper.

Step 4

4 Gradually add milk and cook until mixture is smooth and bubbly, stirring constantly.

Step 5

5 Cook over medium heat until mixture boils, stirring constantly.

Step 6

6 Turn heat to low and simmer 1 minute, stirring constantly.

Step 7

7 Gradually mix in cheese and stir until cheese is melted.

Step 8

8 Add pasta; mix lightly. Pour into 2-quart casserole.

Step 9

9 Top with croutons. Bake uncovered for 25 minutes or until internal temperature reaches 165-175 degrees.