Clean beans and rinse in cold water once or twice until water runs clear.
Cover beans with hot water and soak overnight.
Place hot water in a large pot that has a tight-fitting lid. Add pinto beans,
garlic clove, onion and water. Bring to a boil and lower heat to medium, keeping
it at a simmer. Cook, covered, for 2 or 3 hours or until tender. If more water
is needed always add boiling water, a cup or so at a time.