In a large skillet (12 inch - like this one) over medium heat, heat the oil for 1 minute. Add the onion, pepper, and garlic. Sauté for a few minutes until they start to get soft. Add the ground turkey. Sauté until browned and almost cooked through, breaking up with a spoon as you go— about 7-8 minutes.
Stir in the tomato paste, vinegar, Worcestershire sauce, mustard, and ending with the chicken stock. Then reduce to medium-low heat, cover and allow to simmer for 10 minutes.
Scoop the hot mixture onto a bun and add a slice of Tillamook Extra Sharp White Cheddar Cheese. Serve on a bun.
Make ahead tip: This can be made in advance and stored in the refrigerator for up to 4 days. To reheat, heat the mixture over medium heat in a large skillet or in the microwave. This can be frozen in an air tight container for up to 3 months. Allow to thaw overnight in the refrigerator and heat as desired.1. Use your preferred meat: ground turkey (any fat %) or ground beef.2. For gluten-free, use a certified gluten-free brand or omit the bun.