BLEND Roma tomatoes, olive oil, salt, and dried oregano with a blender, food processor, or immersion blender until it turns into a liquid.
POUR the contents into a medium-sized saucepan, turn to high heat, and bring to a boil.
BOIL for 5 minutes, then reduce heat to low and simmer for 45 minutes.
STRAIN the sauce through a fine-mesh sieve if it still contains some liquid.
PREHEAT oven to 350 F. Line a large baking sheet with parchment paper.
PLACE on the parchment-lined baking sheet. Flatten out the dough and form a circle and bake for 15 minutes.
TOP with fresh marinara sauce, fresh mozzarella, and fresh basil.
BAKE for an aditional 15-20 more minutes.