Chicken Cordon Bleu Burgers (Breaded & Baked)

Name: Chicken Cordon Bleu Burgers (Breaded & Baked)
Prep time: 15 min
Cook time: 15 min
Total time: 30 min
Cuisine: American, French
Ingredients: 1 pound ground chicken (extra lean, about 450g); 1/3 cup smoked turkey ham (finely diced, about 55g); 1/3 cup Swiss cheese (finely diced, about 40g); 2 tablespoons onion (finely minced); 1/4 teaspoon salt (optional); 1 pinch white pepper (to taste); 2 medium eggs (divided, see directions below); 1 tablespoon water; 1/2 cup all-purpose flour (for dredging, about 65g); 1/2 cup panko bread crumbs (or seasoned bread crumbs of your choice, about 30g); 1 teaspoon cooking spray (for greasing the baking sheet); 4 medium crusty whole wheat buns (toasted); 1/2 cup mayonnaise (about 115g); 1 teaspoon sweet paprika; 1 teaspoon dried tarragon (or 2 teaspoons fresh tarragon leaves, finely chopped); 1 teaspoon Dijon mustard; 4 leaves butter lettuce or green leaf; 1 medium tomato (sliced into 4 rounds)