Preheat oven to 375°F.
In a large bowl, beat softened cream cheese with an hand mixer until smooth. Add sour cream. Set aside.
8 ounces cream cheese, 1 cup sour cream
Melt butter in a large skillet over medium-low heat. Add brown sugar and onions. Saute 10-15 minutes until lightly caramelized.
1 large yellow onion, 1 1/2 Tablespoons light brown sugar, 4 Tablespoons salted butter
Add green pepper and garlic. Cook for a few minutes more until peppers are tender, stirring occasionally.
1 large green bell pepper, 3 garlic cloves
Transfer the sauteed peppers and onions to the bowl of cream cheese and sour cream. Add the chopped roast beef, salt and all but 1/2 cup of the provolone cheese, reserving part of the cheese for sprinkling on top at the end. Stir until everything is well-combined.
1/2 pound deli roast beef, 16 ounces sliced Provolone cheese, 1 teaspoon Kosher salt
Transfer the mixture to a pie plate, baking dish, or just use the oven-safe skillet used for sauteeing the vegetables. Sprinkle the remaining provolone cheese on top.
Bake for 25-30 minutes until hot and bubbly, and the provolone cheese starts to slightly brown on top. Serve immediately with sliced baguette, tortilla chips, pretzels, or veggies.
Sliced baguette, Tortilla Chips, Pretzels, Carrot sticks or other vegetables for dipping