Preheat the oven to 400 degrees F. Line a large baking sheet with parchment paper. Place halved tomatoes and garlic cloves on the baking sheet and drizzle with 3 tablespoons of olive oil. Generously season with salt and pepper. Roast in the oven for 40-45 minutes.

While the tomatoes are roasting, you can make the caramelized onions: Add 1/2 tablespoon olive oil to a large pot and place over medium heat. Add the onion slices and stir to coat the onions with olive oil. Cook, stirring occasionally. Check onions every 5-10 minutes until they have completely caramelized and turned golden in color. This usually takes 20 minutes.

Once tomatoes and garlic are done roasting, allow them to cool for 10 minutes, then add them to a food processor with caramelized onions and basil or high powered blender and process for a chunkier sauce or blend completely for a smooth tomato pasta sauce. Alternatively you can add the tomatoes to the large pot and use an immersion blender. It's really just about what you have available to you!

After blending, transfer back to the pot, turn to medium low heat and add in oregano and salt and pepper to taste. From there you can add in any additional add-ons you want (as listed in the ingredients). Serve with your favorite pasta! Serves 4.