Heat the grill to high. Lightly toast the crumpets in a toaster or under the grill. Meanwhile, mix the passata, ketchup and oregano together in a bowl. Season. Chop your chosen toppings into small pieces – young children can tear basil, or chop soft veg in a cup using safety scissors.
Line a baking tray with foil. Spread the sauce over the crumpets, then top with the veg and cheese. Arrange on the tray and grill for 3-4 mins, until the cheese is golden and bubbling. Leave to cool slightly before eating.