Easy Chicken Avocado Melt Sandwich (Crispy and Melty) - My Home Made Recipe

Ingredients

• Boneless skinless chicken breasts (2).
• Salt and pepper to taste.
• Olive oil (1 tablespoon plus more for grilling).
• Ripe avocado (1).
• Sliced cheese of choice (4 slices).
• Bread slices (4).
• Mayonnaise (2 tablespoons).
• Dijon mustard (1 tablespoon).
• Red onion, thinly sliced (1 small).
• Tomato, sliced (1).
• Butter or olive oil for grilling.