Step 1

Bring a large pot of lightly salted water to a boil. Add pasta and cook, stirring occasionally, until tender yet firm to the bite, about 11 minutes. Drain pasta and reserve 1/2 cup pasta water.

Step 2

Meanwhile, trim chicken of fat and slice across the grain into thin strips. Toss the chicken strips with pesto in a bowl, using your hands to make sure chicken is well covered.

Step 3

Heat oil in a large skillet over medium heat. Add chicken and cook and stir until no longer pink, 5 to 7 minutes.

Step 4

Stir Alfredo sauce, mushrooms, salt, and pepper into the chicken. Pour reserved pasta water into the Alfredo jar; shake to rinse, then pour into the skillet. Heat just to a boil, then turn off the heat and stir in pasta.