Preheat the oven to 400°F (200°C). Roast the 6 medium-sized tomatoes on a baking sheet until charred, about 15 minutes.

Meanwhile, heat 2 tablespoons olive oil over medium heat in a medium saucepan.

Add the chopped onion and sauté until translucent, about 5 minutes.

Add the minced garlic and chopped jalapeño to the saucepan and cook for another 2 minutes, stirring occasionally.

Allow the roasted tomatoes to cool slightly, then blend until smooth. Pour the tomato puree into the saucepan with the sautéed vegetables.

Stir in the ground cumin, smoked paprika, salt, and black pepper, mixing well to combine.

Reduce the heat to low and let the sauce simmer for 10 minutes to meld the flavors together.

If using, stir in the chopped fresh cilantro just before serving.

If the sauce is too thick, add water a tablespoon at a time until you reach the desired consistency.