Prepare the Filling: In a bowl, combine the shrimp, 4 tbsp (60 ml) olive oil, minced garlic, chopped chili, cumin, fennel seeds, salt, and pepper.
Mix well to coat the seafood.
Set aside to cool completely to room temperature.
Make it Creamy: Once the shrimp mixture has cooled, gently stir in the mayonnaise and fresh chives until everything is evenly combined. This will be your omelet filling.
Cook the Eggs: In a separate large bowl, whisk the 12 eggs until smooth.
Season with a pinch of salt and pepper.
Heat the remaining 4 tbsp (60 ml) of olive oil or butter in a large non-stick skillet over medium heat.
Assemble the Omelet: Pour the whisked eggs into the hot skillet.
Let them cook, gently pushing the cooked edges towards the center and tilting the pan to allow uncooked egg to flow underneath.
When the omelet is about 80% set, spoon the creamy shrimp mixture over one half of the eggs.
Fold and Serve: Carefully fold the other half of the omelet over the filling.
Reduce the heat to low and let it cook for another minute to allow the center to set completely. Slide onto a plate and serve immediately.