Slow Cooker Black Beans

| 2½ cups dried black beans (no need to soak before using) ((or 6 cups canned beans), )

medium onion (, chopped finely)

garlic

chili flakes (, or 1 fresh chili (you can omit the chili if you prefer))

ground cumin

ground coriander

large bay leaf

dried mint ((optional))

mls | 3½ cups vegetable stock

Juice of one lime