Stir in garlic and cook, stirring constantly, for 1-2 minutes, or just until the garlic is soft and fragrant. You don't want the garlic to brown, or it can get bitter.
Add the crushed tomatoes, tomato paste, sugar, salt, pepper, Italian seasoning, and a pinch of red pepper flakes, if using. Stir to combine.
Cover the saucepan.
Let simmer for 20-30 minutes over low, stirring occasionally.
Let the sauce cool for at least 10 minutes before using.
Garlic: Feel free to add more garlic if you like a stronger garlic flavor to your sauce. Sugar: The sugar helps to balance out the sauce. However, you can omit the sugar if you prefer and use a pinch or so of baking soda instead. Salt: The salt can be adjusted to taste. Italian seasoning: If you don't have Italian seasoning, you can use a combination of dried basil, dried oregano, dried thyme, dried marjoram, and dried rosemary. I use this recipe with my homemade pizza dough recipe. Nutrition values are estimates.