1teaspoonDiamond Crystal kosher salt(not fine table salt)
1tablespooncornstarch (use organic to avoid GMOs)
In a medium bowl, whisk together the barbecue sauce ingredients. Set aside.
Season the beef with the kosher salt and black pepper.
Heat a very large, 14-inch skillet, or a double-burner griddle, over medium-high heat, about 3 minutes. Brush with half the olive oil. Add half the beef in a single layer and brown on all sides, about 5 minutes total. Transfer the browned beef to your slow cooker and repeat with the remaining olive oil and the remaining beef.
Pour the barbecue sauce over the beef and stir to combine. Cover, and cook on low for 7.5 hours.
Whisk the cornstarch with the water until smooth. Stir into the beef mixture. Set to high, cover, and cook 30 more minutes, until the sauce thickens.