Add coconut oil to small (8”) cast iron skillet or non-stick pan and heat over medium-high heat.
Add the mushrooms, sprinkle with salt and pepper and cook until nice and golden brown on both sides.
Add green onions and cook until fragrant, about 30 seconds. Pour in the egg whites and sprinkle chopped thai basil and freshly cracked black pepper overtop.
Reduce heat, cover loosely (a pizza pan works wonders for this) and cook for about 5 minutes, until the omelette is completely set and opaque throughout.
Delicately slide omelet onto serving plate and serve immediately.
Notes
*That’s 8 egg whites total. You could also use a combination of whole eggs and egg whites; I like to do 2 whole eggs and 4 egg whites, or 1 whole egg and 6 egg whites.