3 tablespoons fresh lemon juice
1 1/2 tablespoons extra-virgin olive oil
1/2 teaspoon minced garlic
1/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
1/4 teaspoon Dijon mustard
1 cup grape tomatoes, halved
1 cup thinly vertically sliced red onion
2 (6-ounce) cans Italian tuna packed in olive oil, drained and broken into chunks
1 (15-ounce) can cannellini beans, rinsed and drained
1 (5-ounce) package fresh baby arugula
2 ounces Parmigiano-Reggiano cheese, shaved
Directions:
Whisk together first 6 ingredients in a large bowl. Add tomatoes and next 4 ingredients (through arugula); toss. Top with cheese.