Begin by heating the olive oil in a medium skillet over medium heat. Add the chopped onion and cook until it becomes translucent, about 5 minutes. Stir occasionally to prevent burning. The oil should shimmer, an indication it’s ready for the next step.

Once the onion is softened, toss in the minced garlic. This step adds a fragrant aroma that’ll fill your kitchen. Cook for 1-2 minutes until aromatic but not browned. Burnt garlic can spoil the sauce’s flavor.

Next, add the tomato paste, dried oregano, and sea salt. Stir this mixture well for about 2 minutes. This step caramelizes the paste, intensifying the flavors in the sauce.

Open those cans of San Marzano tomatoes. Carefully add them to the skillet, breaking them apart with a spoon as they go in. This creates a rich base for your sauce. Bring the mixture to a gentle simmer.

Add the sugar along with the crushed red pepper flakes. Stir everything together and let it simmer for about 10-15 minutes, allowing those flavors to meld. You may need to adjust the heat level at this stage. Taste and add more red pepper if you’re feeling daring.

Once simmered, take the pot off the heat and finish with the chopped basil leaves. This last step adds a fresh, vibrant note to the sauce.