Ill start sharing my recipes, as I am a crockpot wunderkind.
2 c lentils, 1 Kielbasa
1 can diced tomatoes, lots of chopped carrots, lots of chopped celery, one box beef broth (32 ounces), 3 cups of water.
Lots of garlic powder, some dashes of lowrys seasoning, lots of chili powder.
Throw in on high for 4 or 5 hours, or low for more time.
I think it cost me about 2 bucks a serving–less if you forgo the meat, or use a cheaper kielbasa (I am an all beef purist). I probably have 8 meals out of this. No carbs, very, very little fat. Really satiating.