1. Pat salmon fillets dry, season with salt and pepper.
2. Heat olive oil in a frying pan over medium heat for 1 minute. Place salmon skin-side down and cook for 3 minutes.
3. Flip salmon, add asparagus, sauce, and water. Cook for 1 more minute while basting the salmon with sauce.
4. Add butter and cook on low heat for 1 minute, mixing the sauce and spooning over salmon.
5. Plate and garnish with chopped green onion and lemon.