Veg-packed cheeseburgers

Name: Veg-packed cheeseburgers
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Cuisine: Greek, American, Southern, European, Moroccan, African, Mediterranean
Ingredients: 2 tbsp vegetable oil; 1 garlic clove, crushed; 1 small onion, finely chopped; 100g courgette, grated; 1 large carrot, grated; 50g mushrooms, finely chopped; ¼ bunch of parsley, finely chopped; 75g cheddar, grated; 1 large egg, beaten; 5 tbsp breadcrumbs; 250g beef mince; 4-6 burger buns; lettuce leaves; sliced tomato; sliced red onion; ketchup, mustard and mayo (optional)