Preheat & Season: Preheat the air fryer to 380°F (195°C). Toss chicken cubes with olive oil and seasonings.
Cook Chicken & Pasta: Air fry the chicken for 10-12 minutes, shaking halfway, until golden and cooked through. Meanwhile, boil the fettuccine according to package directions.
Make Sauce: While the chicken and pasta cook, melt butter in a skillet. Sauté garlic for 30 seconds, then whisk in heavy cream and simmer for 2-3 minutes.
Finish Sauce: Reduce heat to low and stir in grated Parmesan cheese until smooth. Season with salt, pepper, and a pinch of nutmeg.
Combine & Serve: Drain the pasta (reserving some pasta water) and add it to the sauce along with the cooked chicken. Toss to coat, adding a splash of pasta water if needed. Garnish with parsley and serve hot.