Heat a skillet over medium-high heat with oil, 2 turns of the pan. Add meat and lightly brown and crumble. Add salt, pepper, ground cumin, coriander, ancho chili powder, oregano, jalapeño pepper or chiles, onions and garlic, and cook until tender. Add beans and stock, reduce heat to low and simmer.
Pit and scoop avocado flesh into a food processor. Purée with salt, lime juice and yogurt or sour cream until smooth.