Freezer-Friendly Chargrill Veg Sandwiches

• 12 slices wholegrain bread
• 2 avocados
• .5 lemon
• 2 capsicum (peppers)
• 2 zucchini
• 6 slices of cheddar cheese
• .25 cup pesto
• 1.5 tbsp lemon, herb garlic seasoning