Sauté: Bring a medium saucepan to medium-high heat. Add 2 tablespoons extra virgin olive oil; swirl to coat the pan. Add 2 teaspoons garlic and let cook until it becomes fragrant, approx. 30 seconds. Add diced onion and let cook until it softens, about 1 minute.
Combine: Add 15 ounces tomato sauce, 6 ounces tomato paste, 2 tablespoons Italian seasoning, 1 teaspoon dried oregano leaves, 1 teaspoon kosher salt and ⅛ teaspoon ground black pepper; whisk to combine. Taste and adjust seasoning, as desired.
Storage: let it fully cool and place in an airtight container in the fridge for up to 2 weeks.
Freezing: once cooled, you can place it in a freezer safe container (make sure there is space in the top for the sauce to expand a bit) and store in the freezer for up to 3 months.
Sweetness: if you think it needs a touch of sweetness feel free to add in a bit of coconut sugar (or granulated sugar) - start with just a 1/4 or 1/2 teaspoon and go from there.