Heat the olive oil in a large Dutch oven or soup pot over medium heat. Add the chopped onion, carrot, and celery, then cook for about 5–7 minutes, stirring occasionally, until the vegetables begin to soften.

Stir in the minced garlic, cumin, dried oregano, and optional cayenne pepper. Cook for about 30 seconds, just until the garlic and spices smell fragrant.

Add the broth, rinsed pinto beans, diced tomatoes with their juices, salt, and black pepper. Bring the mixture to a boil, watching the pot so the broth does not foam over.

Reduce the heat to a gentle simmer and partially cover the pot. Simmer for 15–20 minutes so the beans, vegetables, tomatoes, and seasonings have time to combine.

For a thicker soup, mash some beans against the side of the pot with a spoon, or briefly blend 1–2 cups of soup and stir it back into the pot. Keep the rest chunky for a pleasant contrast of creamy broth and tender beans.

While the soup simmers, combine the diced tomatoes, red onion, cilantro, lime juice, and optional jalapeño in a bowl. Let the salsa stand for 5–10 minutes so the flavors mingle.

Taste the soup and adjust the salt and black pepper as needed. Ladle it into bowls and serve hot with a generous spoonful of fresh salsa on top.