Pour olive oil into a saucepan and warm it over medium heat. Add minced garlic and stir for about 30 seconds, until fragrant. Make sure it doesn't brown, or it will taste bitter.

Pour in the crushed tomatoes and tomato paste. Stir well until the paste mixes into the crushed tomatoes without any lumps. Add oregano, basil, sugar, salt, black pepper, and red pepper flakes if you want. Mix everything so the spices spread evenly.

Lower the heat so the sauce barely bubbles. Cook uncovered for 20 to 25 minutes, stirring every few minutes to prevent sticking. The sauce should be thick enough to coat the back of a spoon. If it's too thin, let it simmer longer. If it's too thick, add a little water.

Once done, remove the sauce from heat and let it cool for about 15 minutes before using it on pizza dough or storing it in a jar.