Gather a 4 quart or larger slow cooker. You'll also need a large skillet, a colander, and a small mixing bowl.
Heat a large skillet over MED-HIGH heat. When hot, add a drizzle of oil (we normally use avocado oil), and then add beef. Cook, breaking apart into crumbles as it cooks, about 5-8 minutes, or until browned and cooked through. Transfer to colander to drain.
Transfer cooked beef from the colander to the insert of a slow cooker. Add chopped onion, bell pepper, and garlic. Stir well.
In a small mixing bowl, add the tomato paste, ketchup, bbq sauce, brown sugar, worcestershire, dijon mustard, smoked paprika, salt, and pepper. Stir well to combine.
Pour the sauce into the slow cooker on top of the beef mixture. Stir well, then cover and cook on LOW for 4-6 hours, or HIGH for 2-3 hours. ** I recommend stirring the mixture every hour or 2 if you're home, to prevent any burning. **
Before serving, stir well, breaking up any clumps of beef. Serve hot over hamburger buns (toasted buns work perfectly!), or as desired.
