Preheat your oven or indirect grill (I made these on my CampChef Pellet Grill) to 350 degrees.
In a 12 inch cast iron pan, heat the tablespoon of olive oil over medium heat. Saute the onions until just translucent, about 4-5 minutes. Add in the garlic and cook for another 2-3 minutes. Stir in the lentils and chicken stock and simmer for 15 minutes. There will still be liquid remaining and the lentils will be slightly crunchy,
Stir the ketchup, brown sugar, mustard, and spices into the lentils. Transfer the skillet to the grill or oven and cook for an hour, stirring occasionally.
When the liquid is absorbed and the lentils are soft, stir in the crumbled bacon and serve.