Step 1

Whisk together the stock and flour in a 5- to 6-quart slow cooker until blended. Place the shallots, mushrooms, Marsala, and rosemary in the slow cooker. Sprinkle the chicken with the salt and pepper; arrange the chicken in the slow cooker, nestling it among the vegetables and liquid. Cover and cook on LOW until the chicken is tender and the sauce has thickened, about 4 hours.

Step 2

Transfer the chicken from the slow cooker to a serving platter, reserving the cooking liquid and vegetables in the slow cooker. Transfer the cooking liquid and vegetables to a 2-quart saucepan; bring to a boil over medium-high. Boil, stirring occasionally, until the sauce is reduced to 2 cups, about 5 minutes.

Step 3

Cook the linguine according to the package directions, omitting the salt and fat; drain. Divide the linguine among 4 bowls; serve the chicken over the pasta. Top with the sauce. Sprinkle evenly with the parsley.