1 medium onion, finely chopped
1 green bell pepper, finely chopped
1 tablespoon butter (or oil)
1/2 teaspoon EACH: Italian seasoning, garlic powder, AND onion powder
1/8 – 1/4 teaspoon cayenne
2 (8 ounce) blocks full fat cream cheese, room temp
1/4 cup mayonnaise
2 tablespoons sour cream
2 teaspoon red wine vinegar
1 lb. deli-sliced roast beef, chopped (see notes)
2 1/2 cups shredded provolone cheese
Heat the butter in a skillet over medium-high heat. Add the onions and a pinch of salt. Stir as needed and let them soften and turn translucent, about 4-5 minutes. Add the bell peppers and let them cook for 1 minute, remove from heat. Stir in the Italian seasoning, garlic powder, onion powder, and cayenne. Allow the mixture to cool to room temperature before adding to the dip mix.
Position a rack in the center of the oven and preheat the oven to 400ºF. Add the cream cheese to a large bowl and whip it using a hand mixer for 30 seconds. You can also do this with a rubber spatula. The cream cheese should still have some resistance to it. Add the mayo, sour cream, and red wine vinegar and mix it together using a rubber spatula. Season with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Stir in the sautéed veggies, roast beef, and 1 1/2 cups of shredded cheese.
Spray a cast iron skillet or a 9×9 baking dish with nonstick cooking spray; add the prepared dip. Flatten out the dip and top with the remaining shredded cheese. Place the dish on a baking sheet to prevent spill over in the oven. Bake the dip for 20-25 minute. You can also pop it under the broiler for the last 1-2 minutes to get the cheese extra bubbly on top! Serve warm.