Sauté the asparagus with salt, pepper and oil (or possibly a knob of butter) for about 10-15 minutes.
Beat the eggs well with the milk, salt and pepper.
Meanwhile, preheat a pan with a small knob of butter.
Pour the mixture into the pan, adjust to low heat and cover with a lid for about 4-5 minutes. Do not flip the omelette over.
Slide the omelette onto a plate and garnish with the asparagus, sliced avocado and Prosciutto di San Daniele.