In a large pot of salted water cook the penne pasta according to the package directions.
Meanwhile in a large skillet melt 1 tablespoon of butter and add the chicken. Cook over medium heat until the chicken is warm. Add the heavy cream until it bubbles, 1 minute. Set aside.
Drain the pasta and add it to the skillet with the chicken. Fold in the remaining butter until melted. Add the Parmigiano and the heavy cream. Stir until the cream and the cheese are absorbed. Add a dash of nutmeg and freshly ground black pepper.