Preheat your gas or charcoal  grill to 350°-400°F. Oil the grill's grates to prevent the sausage from sticking. Slice the sausage into 1/2" thick rounds. You should get 20 slices (if you get more that's okay). 

Bring about a gallon of water to a rapid boil in a large stock pot. Add the salt once the water has begun to boil. Stir the penne into the boiling water and reduce the heat to med-high to prevent the water from foaming up and boiling over. Cook the pasta for ten minutes, or until al dente. *The package instructions should indicate cook time for al dente. 

While the pasta is boiling, grill the sausage on one side for 3 to 4 minutes before flipping and grilling the other side for an additional 3-4 minutes. Remove the sausage from the grill and keep warm in an oven set to low, or in the microwave. 

Once the pasta has finished cooking, drain it in a colander. Return the pasta to the stock pot and stir in the pesto sauce. Toss the pasta well to make sure it's completely coated. 

Immediately spoon the pasta onto dinner plates, dividing the pasta equally. Top each portion with five pieces of sausage, and a sprinkle of grated cheese, if desired. Enjoy!