Wash and dry produce.

Halve, peel, and finely dice onion. Core, deseed, and finely dice green pepper. Zest and quarter lime. Trim and discard root end from lettuce; separate leaves. Gently crush tortilla chips in their bag into small pieces.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add onion, green pepper, and chicken. Season with salt and pepper. Cook, breaking up meat into pieces and stirring occasionally, until onion is slightly softened, 2-3 minutes.

Add Fajita Spice Blend; cook, stirring, 30 seconds.

Stir in stock concentrate, 1 TBSP water, and ½ tsp sugar (2 TBSP water and 1 tsp sugar for 4 servings). Cook, stirring occasionally, until chicken is browned and warmed through, 2-3 minutes more.

Meanwhile, in a small bowl, combine sour cream, lime zest, and juice from one lime wedge (two wedges for 4 servings). Add water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt and pepper.

Remove pan with chicken mixture from heat; sprinkle with Monterey Jack. Cover pan until cheese melts, 1-2 minutes.

Divide lettuce leaves between plates; fill with cheesy chicken filling. Drizzle with lime crema and sprinkle with crushed tortilla chips. Serve with remaining lime wedges on the side.