Preheat the oven to 325 degrees Fahrenheit.
Heat a saute pan over medium heat and add the bacon slice. Cook for about 3-4 minutes per side until crispy. Remove bacon from pan and set aside to drain excess oil.
In the same pan, add chopped onions, salt, pepper, and thyme leaves. Cook for about 10 minutes until onions are very soft and beginning to brown. Turn off the heat, then add bone broth, Worcestershire sauce, and tomato paste. Stir to combine, then set aside to cool.
In a large bowl, gently combine bison, lamb, rice cake crumbs, egg whites, and onion mixture. Pour into a large loaf pan lined with parchment paper.
Spread ketchup evenly on top of the meatloaf mixture. Crumble the bacon slice and sprinkle over the top.
Bake the meatloaf for about 1 hour and 30 minutes or until the meat is cooked through. Enjoy warm with your favorite sides veggie and mashed potatoes!