Season chicken with 3/4 teaspoon salt and 1/2 teaspoon pepper.
Set a 6-qt Instant Pot® to the high saute setting. Melt butter; add chicken, and cook, stirring often, until golden brown, about 3-4 minutes. Stir in garlic until fragrant, about 1 minute; set aside chicken.
Stir in wine, scraping any browned bits from the bottom of the pot.
Stir in chicken stock, heavy cream and pasta; top with chicken. Select manual setting; adjust pressure to high, and set time for 6 minutes. When finished cooking, natural-release for 5 minutes first, then quick-release pressure according to manufacturer’s directions.
Stir pasta; let mixture stand, stirring occasionally, until half the liquid has reduced, about 3 minutes.
Stir in Parmesan until melted, about 1 minute; season with salt and pepper, to taste.
Serve immediately, garnished with parsley, if desired.
Notes
Choose a wine you will drink. A dry white wine (pinot grigio or sauvignon blanc) is great here – it does not have to be anything fancy or overpriced. Just something you don’t mind sipping on since you will have an open bottle.
Use good-quality stock. The better quality your stock, the better your alfredo sauce. Many brands love to pack in the salt so always opt for unsalted or a lower-sodium variety. Homemade stock is even better.
Freshly grated cheese goes a long way. While pre-grated Parmesan cheese will save a few minutes in the kitchen, freshly grated Parmigiano Reggiano or domestic Parmesan is ideal. This gives the favorited rich, nutty flavors of alfredo sauce, creating a smooth, creamy consistency.
Let the pressure naturally reduce for a few minutes. Letting it sit for about 5 minutes will help avoid a sudden burst of starchy water from the release valve.
Mix it up. Swap out the fettuccine noodles for penne or rotini, use chicken breasts (or tenders) instead of thighs or add in leafy greens, mushrooms, peas or broccoli florets for sneaked-in veggies and nutrition.
Use a bigger Instant Pot when doubling. When doubling the recipe, opt for an 8-qt Instant Pot® instead to allow for enough room, filling just before the max line.