Preheat your oven to 350°F (175°C).

Carefully cut the loaf of French bread in half lengthwise and lay the halves cut-side up on a baking sheet.

In a small bowl, combine the softened butter, grated parmesan, garlic powder, and kosher salt. Spread this mixture generously over the top half of the bread.

Layer the thin slices of ham, pepperoni, and salami on the bottom half of the bread and finish with provolone cheese on top.

Place the sandwich on the middle rack of your oven and bake for approximately 15 minutes or until golden brown and bubbling.

While the sandwich bakes, whisk together mayonnaise, red wine vinegar, Italian seasoning, salt, pepper, and garlic powder in a medium mixing bowl.

Fold in the shredded iceberg lettuce, diced tomatoes, and sliced pepperoncini into the dressing.

Once baked, remove the sandwich from the oven and top generously with the salad mixture, then place the top half of the bread back on.

Slice the Baked Italian Grinder Sandwich into four equal pieces and serve hot.