I agree with Kitty Gold. My dad always said he felt like we were poor when we had lentils, but I say, "Not so!" It's one food I grew up with (German extraction), so to me it's "comfort food."
Follow package directions. You can add in any of the following: cooked potatoes, carrots, sauteed onions (finely chopped), cocktail sausages, sliced frankfurters, etc. A little salt and garlic powder can help, too. Make small additions and taste as you go. You can put more of something in, but you can't take it out.
Most Germans like this thickened with a little flour, and flavored with a little vinegar, but we also eat it thinner, as a soup.
I like mine thick, about the consistency of chili.
This is a warm, comforting, satisfying meal that will leave you feeling full for hours, and it's not expensive at all. It also happens to contain a lot of protein and fiber, both of which are pluses.