Heat the ghee in a large skillet until hot but not smoking. Add the onion, cumin, garlic, salt, pepper, and potatoes and cook until the potatoes soften—about 5 to 8 minutes. Add the peppers and cook until soft, about 4 to 5 more minutes. Add the baby spinach to the pan. Whisk the eggs in a bowl, then add them to the pan, stirring constantly to scramble them. Divide the egg mixture between the collard green leaves and roll up into a burrito-style wrap.