Spread diced sweet potatoes out on a baking sheet. Toss with old bay spice and olive oil. Bake in a preheated 425-degree oven for 30 minutes or until soft.

In a pot, combine lentils and vegetable stock. Bring to a boil over high heat. Reduce heat to medium-low, cover, and simmer until bean become tender. This takes about 30 minutes, and you should stir occasionally so beans don't stick to the bottom of the pot.

Cook onions and olive oil in a different pot over medium heat for 4 minutes or until the onions have softened and turned translucent. Add the tomatoes and garlic, cooking for 5 minutes. Stir in tomato paste, ketchup, mustard powder, chili powder, molasses and Worcestershire sauce; simmer 5 to 10 minutes until sauce thickens.

Drain lentils and reserve cooking liquid. Stir lentils into sauce mixture, adding cooking liquid or water as needed to obtain the desired "sloppy joe" consistency.

Saute kale in a skillet with olive oil until it becomes soft & wilted, about 8 minutes.

Serve sloppy joes on hamburger buns with the sauteed kale and roasted sweet potato. A great weeknight meal!