1. Assemble a solar cooker out in the sun.
2. Butter a piece of bread and place it on the pan, buttered side down.
3. Place the cheese slice on it.
4. Sprinkle the shredded mozzarella.
5. Top with another piece of bread.
6. Butter the bread on the top.
7. Let it sit on the sun and flip it after an hour.
8. Let the other side be cooked for another 30 minutes.
9. Cut the slice in half and serve with the warm cheese oozing out.