Add beef, garlic, pepperoncini + brine, onion, seasonings, bouillon, and water to the CrockPot. Cover and cook on low for 7–9 hours or high for 5–6 hours, until the beef shreds easily with a fork. Remove beef, shred with two forks, and discard large pieces of fat. Return beef to CrockPot.: When you first add the ingredients, notice the sharp, vinegary scent of the pepperoncini peppers mingle with the warm, earthy aroma of Italian seasoning and garlic . As the hours pass the kitchen fills with a rich, savory perfume, and the broth will look darker and glossy, signaling that collagen is breaking down into gelatin which creates that luscious mouthfeel. Use a gentle touch when shredding the beef with two forks, and keep an eye out for any large pieces of fat that stand out visually so you can remove them for a cleaner texture. A common mistake is trying to shred before the connective tissue has fully softened, which results in tough strings; if the forks meet resistance, give it more time. Returning the shredded beef to the jus lets the flavors marry and keeps the meat moist for serving.
Preheat oven to high broil (rack in center). Halve hoagie buns, spread with butter, and sprinkle with garlic powder. Broil for 30–60 seconds, watching closely, until lightly toasted.: The moment the buns enter the oven you ll hear a quick whisper of heat as the edges begin to crisp and the butter sizzles, producing a toasty, nutty aroma. Place the rack in the center so the tops toast evenly without burning. Watch closely because broilers can go from lightly golden to charred within seconds; that short window is the trick to achieve a crisp exterior while maintaining a tender interior. If the surface browns unevenly, rotate the pan for even color. A frequent error is walking away during broiling and returning to over browned or bitter buns, so stay attentive.
Remove the buns from the oven, add provolone cheese to both sides, and broil again for 30–60 seconds, or until the cheese is melted.: Once you add the provolone cheese , the oven s heat will coax it into smooth, glossy pools that drape the bun edges. The smell shifts to a warm, milky note that pairs beautifully with the meaty aroma waiting in your slow cooker. Keep the buns under the broiler just long enough to melt the cheese, watching for bubbling and slight stretching when you jiggle the pan. Overbaking will make the cheese brittle rather than gooey, so pull them out at the first signs of full melt.
Use tongs to shake off excess liquid before placing beef on the bottom buns. Add extra pepperoncini peppers on top if desired. Top with the cheesy bun tops.: Before assembling, use tongs to lift portions of the shredded beef and give them a brief shake to drain excess jus; the meat should still be moist but not swimming, so the bun holds together. You ll see steam rise and smell concentrated meat perfume as you plate. Adding extra pepperoncini peppers at this stage increases brightness and textural contrast, and the melted provolone cheese on the top bun helps secure everything once you close the sandwich. A common pitfall is overfilling the bun, making it difficult to eat cleanly, so find a balance between juicy and manageable.
Serve immediately with a small bowl of the broth from the crockpot for dipping. Enjoy!: Serving a small bowl of warm jus alongside invites that classic dunking ritual, and you ll hear gratifying slurps and see saucy drips as people dip with abandon. The broth should be glossy and flavorful, carrying the seasoning of beef , bouillon , and pepperoncini . Keep the broth hot until you serve to preserve its silky texture. One mistake to avoid is letting the jus cool too much, which makes it less satisfying for dipping and dulls the aromatic experience.