Scrub, peel and rinse the asparagus and cook for 5 - 10 minutes in boiling salted water.
Strain them and douse with cold water. Cut spring onion into small stripes. Mix well olive oil, lemon juice, salt, pepper and sugar. Add asparagus and spring onion stripes. Mix well and let it sit.
Spice chicken breasts with salt and pepper. Heat oil in a pan and fry chicken of both sides until well done. At last spice with rosmary and thyme. Cut into slices and serve with asparagus salad.