Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a large bowl, combine the ground beef, almond flour, egg, Worcestershire sauce, onion powder, garlic powder, salt, and pepper. Mix gently and shape into about 16 meatballs. Place on the prepared baking sheet and bake for 20 to 22 minutes until cooked through and browned.
While the meatballs bake, melt 1 tablespoon of butter in a skillet over medium-high heat. Add the diced green bell pepper and onion with a pinch of salt. Sauté for 6 to 8 minutes, stirring occasionally, until softened and lightly charred. Remove from the skillet and set aside.
In a small saucepan over low heat, combine the butter, cream cheese, and heavy cream. Stir until the cream cheese is melted and smooth. Add the shredded provolone and garlic powder, stirring constantly until you have a silky, pourable cheese sauce.
Arrange the baked meatballs on a serving platter or in a baking dish. Spoon the sautéed peppers and onions over the top of each meatball.
Pour the warm provolone cheese sauce generously over everything. Serve immediately while the cheese sauce is still hot and flowing.