I interpreted it not as her saying that she wouldn't make the pizza he wanted. She did. She was saying that you can't have a pizza marinara with mozzarella beca

I interpreted it not as her saying that she wouldn't make the pizza he wanted. She did. She was saying that you can't have a pizza marinara with mozzarella because it's a contradiction. Like black coffee with milk. You can of course add milk but then it's a white coffee. As you can add mozzarella but then it's a margherita.