In a saucepan, cover the lentils with filtered water and let soak at room temp. for a few hours, or overnight. Drain the lentils in a colander.

Set the empty saucepan on medium-low heat; melt the butter. Add the onion and garlic and saute, stirring occasionally to prevent burning.

Add the stock, lentils, and tomatoes (including juice) to the pot. Bring to a boil. Turn heat down to medium-low, cover the pot, and let the lentils simmer until soft. Add more broth if all the liquid is absorbed.

Salt well to taste. Serve lentils in bowls with plenty of fresh bread on the side!