Whisk eggs together with Old Bay and cayenne. Set aside.Stir together all garlic yogurt sauce ingredients and set aside.Preheat an omelette pan to just under medium heat. Add butter, and let it melt. (Do not let the butter brown.)Pour eggs into pan, swirl eggs around pan to spread out the mixture.
Sprinkle salt and the green onion evenly across the eggs. Add the crumbled cheese and crab to the mixture.DON'T TOUCH your omelette for about 2-3 minutes.
Once the edges of the eggs start pulling away from the pan and appear crisp, use a plastic spatula to fold (or roll) the omelette together.Remove from heat immediately, even though the inside will still appear runny, because the inside will continue cooking from the heat of the surrounding egg.
Serve omelette immediately along with the garlic yogurt sauce. Serve extra green onion and sliced avocado if desired.
Notes
Makes 1 large omelette; Serves 2.Tip: The avocado could also be added to the omelette while cooking (if preferred), but I've found that extra ingredients sometimes make the omelette harder to roll or flip.