Broccoli macaroni cheese

Name: Broccoli macaroni cheese
Prep time: 5 min
Cook time: 20 min
Total time: 25 min
Cuisine: American
Ingredients: 300g Co-op macaroni; 1 Co-op broccoli head, cut into florets; 30g Co-op unsalted butter; 1 heaped tbsp Co-op plain white flour; 400ml Co-op semi-skimmed milk (or 300ml milk and 100ml cooking water); 120g Co-op grated mature Cheddar