Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
Sauté the sliced onions, bell peppers, and mushrooms for 5-7 minutes until tender and caramelized.
Remove vegetables from the skillet and set aside.
Add the remaining olive oil to the skillet and increase heat to high.
Add the steak in a single layer and season with salt, pepper, and garlic powder.
Sear for 2-3 minutes until browned, then return vegetables to the pan.
Toss to combine and reduce heat to low.
Layer provolone cheese slices over the mixture and cover for 60 seconds until melted.
Divide cauliflower rice into four bowls.
Portion the cheesesteak mixture over the cauliflower rice and serve immediately.