1 pound dry pinto beans
4 slices thick-cut bacon, cubed
1 onion, diced
2 cloves garlic, minced
1 tablespoon chicken fat
1 tablespoon chicken stock concentrate
1 sprig thyme
1 bay leaf
salt, to taste
Place the beans in a pot and cover by about 2 inches with water. Bring to a boil, boil for 10 minutes, then drain. Set aside.
Add the bacon to the pot and cook over medium heat until the bacon is crisp and the fat has been rendered. Remove the bacon with a slotted spoon and add the onion. Cook, stirring occasionally, until soft and slightly browned, about 10-15 minutes. Add the garlic and cook until fragrant (about 1 minute).
Add the chicken fat, chicken stock concentrate, thyme, bay leaf, reserved beans, and reserved bacon to the pot. Add enough water to cover the beans by about 2 inches. Bring to a boil, then reduce to a simmer.
Cook the beans at a low simmer, stirring occasionally, until they are tender. Season to taste with salt, and then continue cooking until they are easily crushable and very tender. (This can take anywhere from 3-4 hours, depending on the age of your beans.)
Remove the bay leaf before serving.