Peel the sweet potato and chop it very roughly (2 cm edge length). Peel the potatoes and dice them a little finer (about 1 cm edge length). Clean the peppers and roughly chop them into pieces. Peel the onion and chop it very roughly. Peel garlic and chop finely.
Put everything together in a baking dish and mix, stir in a little olive oil, salt and pepper. Put in the oven and bake for about 45-50 minutes.
If you want to eat halloumi with it, cut it into slices and place it on the vegetables about a quarter of an hour before the end of the baking time - if you want to eat mozzarella, cut it roughly and mix it with the vegetables after baking.