In a medium saucepan, pour in 3 tablespoons of olive oil and set the heat to medium. Allow the oil to warm for about 2 minutes until it shimmers gently.

Add one finely chopped yellow onion to the hot oil. Cook for about 5 minutes, stirring occasionally, until the onions turn translucent and soft. Then, introduce 3 minced garlic cloves and continue to stir for another 1-2 minutes.

Sprinkle in 2 tablespoons of all-purpose flour, stirring continuously for about 2-3 minutes. This helps to cook out the raw flour taste while blending it into the onion and garlic mix.

Next, add 1 cup of chopped tomatoes, 1 tablespoon of sweet smoked paprika, and 1 teaspoon of spicy paprika to the saucepan. Stir these ingredients together, cooking for another 3-4 minutes.

Pour in 1 cup of vegetable stock and 1 tablespoon of sherry vinegar, stirring well to combine. Raise the heat slightly and bring the mixture to a gentle simmer for about 10 minutes.

After simmering, remove the saucepan from the heat. Using a hand blender, blend the mixture until completely smooth.

Finally, taste your sauce and adjust with salt as needed. Let it cool completely before transferring it to an airtight container.