Beans cooked "with poison" — a playful name for beans with dried avocado leaves for seasoning. This vegetarian, protein-rich Oaxacan family dish gets its unique flavor from a surprising ingredient.
Rinse the dried pinto beans thoroughly, then soak them in water overnight for optimal tenderness.
Drain and place beans in a large pot; add 6 cups of fresh water, the whole onion, and crushed garlic cloves.
Bring to a simmer over medium heat, then lower to gentle heat and cover; cook for about 1 hour, stirring occasionally to prevent sticking.
Add dried avocado leaves, salt, and black pepper; continue cooking uncovered for another 30 minutes, letting flavors infuse and liquid slightly reduce.
Remove the onion and avocado leaves; stir in olive oil and simmer for an additional 10 minutes over low heat for a silky texture, then serve hot.