- 1/2 cup diced red onion
 - 1/3 cup light mayonnaise
 - 1/4 teaspoon kosher salt, or to taste
 - Freshly ground pepper to taste
 - 2 (6 ounce) chunk light tuna in olive oil, drained
 - 2 stalks celery, thinly sliced
 - 1/4 cup packed coarsely chopped fresh tarragon leaves
 - 8 cups torn lettuce or mixed greens
 - 1 pound small ripe tomatoes, cut into wedges
 - 1 lemon, cut into wedges
 
- Place onion in a small bowl and cover with cold water. Refrigerate for 20 minutes. Drain.
 - Whisk mayonnaise, salt and pepper in a medium bowl. Add tuna, celery, tarragon and the drained onion; stir to combine. Serve on a bed of lettuce (or mixed greens) with tomato and lemon wedges.