Prepare the Beans: Rinse and sort the navy beans. Soak them overnight or use the quick-soak method (boil for 2 minutes, then let sit for 1 hour).

Cook Aromatics: In a large pot, sauté the chopped onions and minced garlic until softened and fragrant.

Combine Ingredients: Add the soaked beans, tomato sauce, brown sugar, ground mustard, cinnamon, salt, and pepper. Stir well.

Simmer & Cook: Add enough water to cover the beans, bring to a simmer, then cover and cook for about 2 hours, stirring occasionally.

Final Touches: Once the beans are tender and the sauce has thickened, adjust seasoning as needed. Serve warm and enjoy!