1/2 lb (250 g) tri-coloured or regular rotini (corkscrew) pasta, about 2-1/2 cups (625 mL)
3 tbsp butter (45 mL)
1 onion, chopped
1/4 cup all-purpose flour (50 mL)
3 cups milk (750 mL)
1 tsp Dijon mustard (5 mL)
1 cup diced ham (1/2 inch/2 cm cubes) (250 mL)
1 cup frozen peas, thawed (250 mL)
1 tsp salt (5 mL)
1/4 tsp pepper (1 mL)
2 cups grated cheddar cheese (500 mL)
Topping:
1 cup fresh bread crumbs (250 mL)
1/4 cup grated Parmesan cheese (50 mL)
2 tbsp melted butter (25 mL)

Preheat oven to 350°F (180°C). Soak a piece of parchment paper large enough to line an 8 cup (2 L) baking dish in water to soften. Drain and shape parchment paper into casserole.

Cook pasta in a large pan of boiling salted water until tender; drain.

Meanwhile, melt butter in a large saucepan over medium heat. Add onion and cook, stirring occasionally for 3 minutes until softened. Stir in flour and cook, stirring for 1 minute. Gradually whisk in milk. Bring sauce to a boil, reduce heat and simmer, stirring occasionally for 5 minutes (sauce will be thin). Remove from heat. Stir in mustard, ham, peas, salt, pepper, cooked pasta and cheese.

Spoon mixture into lined baking dish.

In a small bowl, combine bread crumbs, Parmesan and butter. Sprinkle over pasta. Bake 30 to 35 minutes or until golden and bubbling.

Makes 6 to 8 servings