Begin by preparing the ingredients. Shred the cooked chicken fillet with two forks until fine strips form. Slice the spring onions into thin rings. Remove the leaves from the little gem, wash them carefully under cold water and pat them dry. Lay these lettuce boats aside on the work surface.
Halve the ripe avocado, remove the pit and scoop the flesh into a large bowl. Mash the avocado completely with a fork. Add the sugar-free mayonnaise and stir firmly until a smooth, creamy sauce forms. Fold in the shredded chicken and thinly sliced spring onion into the avocado cream until evenly distributed.
Season the mixture. Add the pinch of chili flakes to give the salad more heat. Sprinkle with salt and pepper to taste. Stir everything once more and taste to check if the flavors are balanced.
Get the prepared little gem leaves. Fill each lettuce boat generously with the chicken-avocado salad. Distribute the mixture evenly over the leaves. Place the filled boats directly on a plate and serve immediately so the lettuce stays nice and crispy.