Mouthwatering Chicken Avocado Melt Sandwich

Ingredients

• 2 chicken breasts, no skin or bones
• 1 avocado, cut into slices
• 4 pieces of your favorite cheese (cheddar, provolone, or Swiss)
• 4 slices of bread, try ciabatta or sourdough
• Freshly cracked black pepper and a pinch of salt
• 2 large spoonfuls of mayo
• 1 spoon of Dijon mustard
• 1 juicy tomato, sliced nicely
• A small red onion, cut into thin rings
• Olive oil for cooking the chicken (about 1 spoon)
• Butter or olive oil to grill the sandwiches