Gouda pasta bake

Ingredients

• 6 oz pasta spirals
• 2 tablespoons oil
• 1 medium onion, peeled and chopped
• 1 lb minced beef or lamb
• 4 sticks celery, sliced
• 2 level tablespoons plain flour
• 13.5 oz can chopped tomatoes
• 1 stock cube, beef or lamb, depending on meat used
• Salt and freshly ground black pepper
• 2 tablespoons butter
• 1 oz plain flour
• 1⁄2 pint milk
• 1 level teaspoon dry mustard powder
• 2 oz Frico Gouda cheese, shredded