Saute about a handful of the onions with the olive oil in a skillet. Once the onions start to appear translucent, add the ground meat and brown. Chop the sweet potatoes into small cubes (see note below for advice on chopping). Microwave the cubes for about 6 minutes to soften them. Turn the crockpot on high and add the remaining onions. When the meat is done browning, drain and add on top of the onions. Pour in the beer & bourbon. In a large bowl, combine all the remaining ingredients & spices and mix together, and then add to the crockpot and give the whole thing a good stirring. Cook for 6 hours on high heat, stirring occasionally. Add additional salt/cumin/oregano to achieve desired flavor, and more chipotle/chili powder for desired heat. Serve with shredded cheese, cornbread, and tortilla chips!