Make the peanut sauce: in a small saucepan combine 1/2 cup chicken broth, 3 tbsp PB2 (or 2 tbsp peanut butter), 1/2 tbsp Sriracha, 1 tbsp honey, 1 tbsp soy sauce, 1/2 tbsp grated fresh ginger, and 1 crushed garlic clove.
Simmer the sauce over medium-low heat, stirring occasionally, until smooth and slightly thickened, about 6 to 8 minutes; remove from heat and set aside.
Heat a large non-stick skillet or wok over medium-high heat and spray lightly with cooking spray.
Add 16 oz ground chicken and sauté, breaking it up with a spatula, until cooked through and lightly browned.
Stir in 1 tbsp Sriracha (or to taste), the remaining 4 crushed garlic cloves, and 1 tbsp grated fresh ginger and cook for 1 minute.
Add 1 tbsp soy sauce and cook 1 more minute to combine flavors.
Stir in 3/4 cup shredded carrots and 1/2 cup of the chopped scallions; sauté until tender-crisp, about 1–2 minutes, then remove from heat.
To assemble, divide the chicken mixture evenly among 8 lettuce leaves. Top each with shredded red cabbage, remaining scallions, a drizzle of peanut sauce, chopped peanuts, and cilantro leaves.
Serve with lime wedges alongside for squeezing over the tacos.