Heat 1 Tbs. olive oil in a large frying pan, until shimmering. Add the onion and cook for 5 minutes, until translucent.
Stir in minced garlic and cook for about 30 seconds, or until fragrant.
Stir in diced tomatoes and Italian seasoning, cooking until slightly thickened, about 15 minutes.
Remove from heat and set aside.
For the pizzas:
Add 1 tsp. olive oil to each well of a cupcake tin.
Roll out pizza dough until about ¼" thick.
Using a biscuit cutter slightly larger than the opening of your cupcake pan, cut out rounds of dough and push them into the cupcake pans. If you don’t have a biscuit cutter, a large cup or small bowl would work too!
Add a heaping Tbs. of tomato sauce to each pizza dough cup.
Top with chopped peppers and shredded mozzarella cheese.
Bake for 15-18 minutes, until the cheese is bubbly and the dough is lightly browned on top.
Remove from the oven and cool for two minutes before removing to a serving tray.
Notes
Mini pizzas freeze well. Place in a plastic freezer bag. To reheat, microwave or heat in oven.