Heat oil in a wok or skillet, cook garlic and shallot for 30 seconds, then add ground chicken and cook until crumbled.
Add green onions, lemongrass, cashews, hoisin, chili garlic sauce, soy sauce, and rice vinegar; toss and simmer for 2-3 minutes. Remove from heat and top with cilantro.
Separate lettuce leaves, spoon filling into each leaf, fold, and serve like tacos.
Notes
For extra flavor, add a squeeze of lime or additional herbs.