Steam asparagus for 3 minutes, rinse with cold water.
Combine parsley, vinegar, lemon juice, olive oil, butter, salt and pepper in a small bowl, wisk to combine.
In a small bowl min beans, tomatoes and 1/4 cup dressing minture. Toss gently.
Place one cup on lettuce on a plate, top with 5 asparagus spears, 1/2 Cup bean/tomato mixture and 1/2 can of tuna. Drizzle with 1 Tablespoon remaining dressing.