In a saucepan, heat the olive oil at medium heat. Add in the grated onion and the minced garlic.
Season with kosher salt and freshly cracked black pepper.
Cook until the onion and garlic are fragrant. About 4-5 min. Add in the can of whole peeled tomatoes. Smash the tomatoes with the back of a wooden spoon to burst and break up.
Season again with Kosher salt and pepper. Turn the heat down to low and place the cover on your pot, slightly uncovered.
Cook stirring occasionally for about 30 minutes. Check seasoning and add more salt if needed. Using an immersion blender or food processor, puree your sauce until smooth. If you have an immersion blender it is perfect here. If not, carefully transfer your tomatoes into your food processor bowl and pulse until the tomatoes have no more chunks and carefully transfer back into your pot to keep warm.
Serve on your favorite pasta dish, baked pasta or on the side as a dipping sauce. ENJOY!