2 cups water
1 cup brown lentils, rinsed
salt to taste (optional)
1 cup chopped onion
15 oz can diced tomatoes (drained), tomato sauce or 2 cups fresh tomatoes, chopped
1 (6 oz) can tomato paste, optional (as needed to thicken – especially if using tomato sauce)
2 cloves garlic, minced
1/2 cup ketchup
1 teaspoon mustard powder
1 tablespoon chili powder
3 tablespoons rapadura, molasses, or honey
1 Tbsp white vinegar
salt and ground black pepper to taste
4 hamburger buns, split
cheddar cheese, grated (to top your lentils when serving)

Combine all your ingredients in the crockpot (besides the buns and cheese!). Turn on low and cook for approximately 5 hours, until lentils are tender and the mixture has thickened and absorbed most of the liquids. Serve on open faced hamburger buns and top with melted cheese, as desired.