Preheat the oven to broil.
Start with freshly baked sourdough bread. I like to use ___ brand, which is half baked when I purchase so I have to go through one more (very worth it) step requiring I finishing backing the bread.
Slice the bread into inch width wide pieces.
Place pieces of bread on a parchment or silicone lined baking sheet. Top with tomato sauce and slices of cheese.
Broil the pizzas until the bread is nice and toasty and the cheese is melted - should take about 10 minutes.