The night before you plan to cook the beans, add dry pinto beans, 1 tablespoon fine sea salt and 6 cups water to the bowl of a slow cooker. Stir to combine; let soak overnight (At least 4 hours and up to 12 hours). In the morning, drain and rinse beans and return to slow cooker.
Heat olive oil in a large skillet over medium heat; add onion, cook and stir 3 to 4 minutes until starting to soften. Add garlic; cook and stir until fragrant, about 30 seconds more. Transfer to soaked, rinsed and drained beans in slow cooker. Add cumin, coriander, chipotle chile powder, oregano, bay leaves, 1/2 teaspoon fine sea salt and fresh water; stir to combine.
Cook on high for 3 to 5 hours (size and age of beans determines cooking time). After 3 hours on high, check beans for doneness every 15 to 30 minutes until they are tender. Remove and discard bay leaves. Serve beans with or without liquid. (recipe note #2)
Notes
Note that time calculation does not include overnight soaking time.
Allow leftover beans to cool in slow cooker for the best texture and flavor; transfer beans along with cooking liquid to an airtight container and store in the refrigerator for up to 1 week or freeze for up to 3 months.