Bring a large pot of generously salted water to a rolling boil. Cook the fettuccine until just al dente — about 1 minute shy of the package directions, since it finishes in the sauce. Before draining, scoop out 1 cup of the starchy pasta water; this is what makes the sauce cling. Drain.

While the pasta cooks, heat the olive oil in a large deep skillet over medium-high heat. Season the chicken strips with the salt, pepper, and Italian seasoning. Sear 3–4 minutes per side until deeply golden and cooked through to 165°F internal, with no pink in the center. Transfer to a plate.

Add the cottage cheese, Parmesan, and half the minced garlic to a blender. Blend a full 60–90 seconds until completely silky with zero visible curds — this step is the entire recipe, so don't rush it. If the blender struggles, add 2–3 tablespoons of milk or pasta water to get it moving.

Reduce the skillet to medium-low heat. Melt the butter, add the remaining garlic, and cook 30–60 seconds until fragrant but not browned — browned garlic turns bitter.

Pour the blended sauce into the skillet and warm it gently, stirring — never let it boil, or the dairy can separate. Add the drained pasta and the seared chicken, tossing with tongs to coat every strand. Splash in reserved pasta water a few tablespoons at a time until the sauce turns glossy and clings.

Divide among warm bowls. Shower with extra Parmesan, chopped parsley, cracked black pepper, and red pepper flakes if you like heat.