Preheat grill to 350°.
Pat chicken dry with paper towels. Brush lightly with olive oil and season with spice rub on both sides.
Cook chicken on a pellet grill. Cook for 10 minutes with the grill closed.
Flip the chicken and brush with chipotle sauce.
Continue cooking with the grill closed another 5 minutes, flip the chicken and brush with chipotle sauce. Cook until chicken reaches 165° using a digital meat thermometer.
Boil the macaroni according to package directions and drain well.
Add milk, cream cheese, garlic, salt, pepper and nutmeg to a large saucepan. Cook over medium heat, whisking until smooth.
Lower the heat and stir in the cheese.
Add the chipotle sauce and whisk until combined.
Next, stir in the cooked and drained macaroni.
Serve chipotle chicken tenders over mac and cheese.