Bring it to boil, then reduce heat and cook for 40 minutes, stirring occasionally so you don’t burn the bottom.
Remove the onion from the pot, mash it with a wooden spoon and put it back. If you don’t like cooked onion, you can just throw it away.
At this moment garlic is already so soft, you can easily crush it with a back of the spoon.
Give it a taste, if it needs more salt or pepper - add more. Blend the sauce if you want to make is smoother.
Serve over pasta, veggies or your protein. Add a fresh basil leaves, if you like.
Video
Notes
Store in a closed jar up to 1 week or freeze in ice cube molds up to 3 months.If you want to use fresh tomatoes, place them first in a boiled water, peel off the skin and use in the recipe. Cook 10 minutes more.