Heat some olive oil in a medium saucepan over medium heat. Add the onions, and cook for a few minutes until the color starts to change. Add the garlic, and cook for 1-2 more minutes.
2 tablespoon olive oil, 1 yellow onion, 2-3 garlic cloves
Add the flour, and cook for at least 2-3 minutes, stirring constantly.
2 tablespoon all purpose flour
Add the chopped tomatoes, sweet and spicy paprika, and tomato paste. Stir well and continue cook for a few minutes.
1 cup chopped tomatoes, ½ tablespoon sweet smoked paprika, 1 teaspoon spicy paprika, 1 tablespoon tomato paste
Pour the vegetable stock and sherry vinegar, and bring the sauce to a gentle simmer. Leave the sauce simmering for about 10 minutes, while stirring frequently. Add salt to season.
1 tablespoon sherry vinegar, 1 cup vegetable stock, 1 teaspoon salt
Transfer the sauce to a hand blender, and blend until you have a smooth Bravas Sauce.
Enjoy on fried potatoes, as a dipping sauce, or even pasta sauce.