Step 1

Coarsely mash beans with a fork or potato masher in a large bowl. Stir in egg, 2 teaspoons mustard, lemon zest, dill, mint and tarragon. Flake tuna into chunks; gently fold into the bean mixture. Sprinkle panko over the mixture; gently fold in until well combined. Form the mixture into 4 (1-inch-thick) patties.

Step 2

Heat 1 tablespoon oil in a large nonstick skillet over medium heat. Swirl to coat the pan. Cook the patties until golden brown on both sides, about 3 minutes per side.

Step 3

Whisk lemon juice, honey, pepper, salt and the remaining 1 teaspoon mustard and 5 tablespoons oil in a small bowl. Divide greens among 4 plates; top each with a tuna cake and drizzle evenly with dressing.