Preheat oven to 180c.
Cook the pasta in a large pot of salted water according to the package directions (less 1 minute), adding in broccoli for the last 2 minutes (see my notes).
250 g pasta, 300 g fresh broccoli florets
Drain and return to the pot, then stir through the butter allowing it to melt then set aside.
2 teaspoons butter
While the pasta cooks, in a jug or small bowl whisk together cream, garlic powder, onion powder, mustard and salt.
300 ml thickened cream, ¾ teaspoon garlic powder, ¼ teaspoon onion powder, 1 tablespoon Dijon mustard, ½ teaspoon salt
Add chicken, parmesan, thyme and cream mixture to pasta and broccoli, stirring well to coat.
300 g cooked chicken, 50 g parmesan cheese, 1 teaspoon fresh thyme leaves
Transfer the pasta mixture into a large baking dish (20 x 30cm/8 x 12"), sprinkle mozzarella cheese over the top and bake for 20 - 25 minutes until brown on top and heated through.
40 g mozzarella cheese