In a quart jar or bowl, layer the sliced cucumbers, carrots, and red onion. In a separate bowl, stir together the vinegar, water, sugar, ginger, salt and red pepper flakes. Microwave for 30-45 seconds until warm. Stir to dissolve the sugar.
Pour the vinegar and ginger mixture over the sliced vegetables. Seal and shake to combine. Refrigerate for at least 30 minutes before serving.
To make a Thai Tuna Lettuce Wrap:
Place desired amount of tuna on top of a leaf of lettuce. Top with the ginger carrot and cucumber pickle mix, a drizzle of Thai chili sauce, fresh cilantro, green onions and almonds.
This recipe will make enough to feed 4 people. The number of lettuce wraps depends on the size of lettuce, the amount of tuna used, etc. Use more tuna as needed.