Step 1: Prep the Tomatoes
Start by washing your tomatoes well and bringing a large pot of water to a boil. While you wait, score a shallow “X” at the bottom of each tomato with a knife, this helps the skin slip off later. Once the water is boiling, carefully place the tomatoes in and let them soak for 5 minutes. After that, drain them and allow them to cool for a few minutes. The skin should now peel off easily with your fingers or a small knife. Cut each tomato in half, remove the core (that firm white or green center), and chop them into rough chunks. Set aside.

Step 2: Sauté the Onion
While the tomatoes cool, finely chop the onion. In a large saucepan, heat 2 tablespoons of olive oil over medium heat. Add the onion and cook for about 5-7 minutes, stirring occasionally, until it becomes soft and lightly golden. This base adds sweetness and depth to the sauce.

Step 3: Combine Tomatoes and Start Cooking
Now add the chopped, peeled tomatoes to the saucepan with your golden onions. Stir everything together well and use the back of your spoon to press down some of the chunks, this helps them break down faster. Add 1 tsp of salt at this stage (you will adjust later based on taste). Let the mixture simmer uncovered over medium-high heat for 25-30 minutes, stirring often. The goal here is to reduce the liquid and create a nice, thick consistency.

Step 4: Taste and Adjust
Once the sauce has thickened up and looks creamy (not watery), it is time to taste. Add more salt if needed, a pinch at a time. If your tomatoes are a bit too acidic, stir in about ¾ teaspoon of sugar to mellow it out – this part is flexible, depending on how sweet your tomatoes naturally are. Let it simmer for a few extra minutes to absorb any final tweaks.

Step 5: Blend and Finish
If you like your tomato sauce chunky and rustic, you are done. But if you want a smoother texture like the classic Chef Boyardee, grab an immersion blender and blend all or just half of the sauce directly into the pot. I personally like blending about half for a balance between silky and hearty.

Now Rinse a few fresh basil leaves, pat them dry, and tear them into pieces. Stir them into the warm sauce just before turning off the heat. The basil adds a final layer of brightness and aroma. Let the sauce cool a bit, then use it right away or spoon it into clean jars.