Burgers with Asparagus and Lemon-herb sauce

Name: Burgers with Asparagus and Lemon-herb sauce
Cuisine: American
Ingredients: 6 tbsp mayonnaise; 2 scallions; 3 tbsp parsley; 1 tbsp lemon juice; 1 slice hearty white bread; 1 lbs ground turkey; 1 tbsp dijon; 2 tsp capers; salt and pepper; 1 lbs asparagus; 1 tsp EVOO; 4 hamburger buns; 1 small head lettuce