Wash the pumpkin thoroughly, remove the skin and seeds, and cut into bite-sized pieces.
Finely chop the onion and tomato.
Heat olive oil in a pan and sauté the onion.
When the onion turns translucent, add the chopped pumpkin and tomato and stir-fry together.
Season with salt and pepper.
Transfer the ingredients to an oven-safe dish.
Evenly sprinkle mozzarella cheese over the top.
Bake in a 200°C oven for 15-20 minutes until the cheese is golden and bubbly.