In a mixing bowl, combine 2 cups of beef stock, sliced pepperoncini with their juices, chopped onion, minced garlic, onion powder, a bay leaf, and Italian seasonings. Stir until well incorporated.

Cut the boneless beef chuck roast into 6-inch chunks and season with salt and pepper.

Heat 2 tablespoons of olive oil in a skillet over medium-high heat. Sear beef chunks for 2-3 minutes until browned on all sides. Transfer seared beef to the slow cooker.

Set the slow cooker to low and cook for approximately 6 hours or until fork-tender.

Remove the beef from the slow cooker and strain the cooking liquid. Bring the liquid to a simmer in a saucepan to reduce.

Shred the beef into bite-sized pieces, mixing in any softened onions and peppers. Garnish with cheese if desired.

Serve the shredded beef on a platter, drizzled with the reduced sauce, over cauliflower rice or in sandwich rolls.