Open-Faced Tuna Melt Sandwich

Ingredients (13)

• + 2 (3 ounce) pouches white albacore tuna, drained add to pantry
• + 3 tablespoons Primal Kitchen™ Avocado Oil Mayonnaise, plus more for spreading add to pantry
• + 2 teaspoons Dijon mustard add to pantry
• + 2 tablespoons finely chopped red onion, or more to taste add to pantry
• ✓ 2 teaspoons capers, drained
• + 2 tablespoons chopped cornichons add to pantry
• + 1 tablespoon lemon juice add to pantry
• + ¼ teaspoon fresh or dried thyme leaves add to pantry
• + Sea salt and freshly ground black pepper to taste add to pantry
• + Sea salt and freshly ground black pepper to taste add to pantry
• + 3 slices whole wheat or whole grain bread add to pantry
• + 6 thin slices tomato add to pantry
• + 3 large slices Gruyere, white Cheddar, or provolone cheese add to pantry