Dice half of the onion, then thinly slice the other half. Preheat a large skillet, then add the olive oil. Once the oil has heated up add half of the onion, garlic, and half of the green bell pepper. Saute for a few minutes or until the vegetables start to soften.
Add the ground beef then season with onion powder, garlic powder, salt, and half the black pepper. Use a potato masher to break the beef up into crumbles.
Cover the pan then cook for a few more minutes, stirring occasionally until the beef is completely cooked through.
Stir in the beef broth, cauliflower, onions, bell pepper, and mushrooms. Simmer for another 15 minutes, then smash the cauliflower down into smaller pieces.
Turn the heat off then stir in the half and half. Season with remaining black pepper, onion powder, and garlic powder.
Lay the provolone slices on top, then cover with a lid and allow the cheese to melt before serving.