To make the chicken salad, in a bowl stir together the mayonnaise, red onion, chives, garlic, mustard, salt & pepper, lemon juice and vinegar. Once well mixed taste to make sure you are happy with the flavour before stirring in the shredded chicken. Set aside.
Lay a large piece of parchment paper (approx 12x12inches) on the counter and place about 8-9 lettuce leaves in a rectangle in the middle of the parchment paper making sure that the overlap.
Place 2 slices of the bacon along with slices of avocado and tomatoes in the middle of the lettuce leaves. Top with have of the chicken salad mixture.
Starting with the end closest to you, use the parchment paper to roll the lettuce up into a wrap, pressing down as tightly as possible. Fold the outside ends of the wrap in towards the middle and once the roll is completely wrapped tightly, wrap any of the remaining parchment paper around the wrap to ensure its tightly encased. Repeat with the second wrap using up the remaining ingredients. (Watch the video above for a demonstration, it should be like you are wrapping a burrito.)
When you are ready to eat, cut the wrap through the middle and enjoy.