Preheat your oven to 350 and spread your cashews across a baking sheet in a single layer. Place in the oven for 10 minutes or until golden and toasty. Set aside to cool and then chop into pieces once cool to the touch.
Combine the chicken broth, hoisin sauce, soy sauce, sugar and cornstarch in a small mixing bowl and whisk together until well combined. Set aside.
Pour the canola oil into a large (12-inch) skillet and bring to medium-high heat. Once the oil is hot, add the garlic and stir. Cook garlic for around 30 seconds until fragrant. Add the ground chicken to the garlic and cook, breaking the chicken up into bite sized pieces using a spatula or wooden spoon, for 4-6 minutes until cooked through and browned.
Add the scallions and the sauce mixture from step 2 and cook, stirring continuously, for another 2 minutes or until sauce thickens. Stir in the basil and cashews until well combine and remove from heat.
Spoon the filling into the lettuce leaves and serve! Each serving is about ¾ cup of filling, so 3 leaves with ¼ cup each is an easy way to create a serving.