Shepherds pie

One yellow onion diced
Three carrots chopped
2 garlic cloves minced
4 medium cooked and peeled sweet potatoes
1 pound of bison
1/2 teaspoon paprika 
1/2 teaspoon cayenne pepper 
1 teaspoon cumin 
1/4 teaspoon salt 
1/4 teaspoon pepper 
1 6oz can of tomato paste 
1 cup chicken stock 
Preheat the oven to 400 degrees. Dice the onion and sweat it in a cast-iron skillet (about 12 inches) for five minutes on medium high heat. Add minced garlic cloves. Sauté for another minute or two. Add a pound of ground bison with the paprika, cayenne pepper, cumin, salt and pepper. Mix thoroughly. Mix in one 6 ounce jar of tomato paste and one cup of chicken stock. Add the chopped carrots and let it reduce for five minutes on medium heat. While it is reducing, put the cooked sweet potatoes into a food processor or high powered blender. Add a splash of chicken stock if necessary. Top with the sweet potatoes and put it in the oven for 20 to 25 minutes at 400 degrees. Let it rest for 5 minutes before serving.