Open the cans of whole tomatoes and remove their seeds with either a seed remover or strainer.
Place tomatoes in a medium bowl. Crush the tomatoes with your hands. For a smoother consistency use a food processor to crush the tomatoes until your desired smoothness is reached.
In a heavy gauge pan, heat olive oil on medium-low heat. Add onions and sauté until they are translucent, about 8-10 minutes. Then stir in garlic and cook for an additional 1-2 minutes. Stir in tomato paste for an additional minute.
Pour sauce into pan stir and heat over medium-low heat for 45-60 minutes stirring occasionally to make sure sauce is not sticking.
Remove from heat and add in fresh or dried spices. Stir to combine. Taste and season as needed.