Slow Cooker Lentil Sloppy Joes are a vegetarian twist on the classic sloppy joes. This recipe replaces ground meat with lentils, which are cooked in a flavorful tomato-based sauce. The lentils become tender and absorb the delicious combination of spices, onions, and garlic. Serve the lentil mixture on toasted buns for a hearty and satisfying meal that the whole family will enjoy.