Fill a large, 1-gallon stock pot with a pasta insert, 3/4 full with water. Bring to a boil over high heat and season with salt to taste. Place the penne in the salted water and return to a boil, stirring occasionally. Cook the pasta until nearly al dente, 10 to 12 minutes. Drain and set aside, reserving 1 cup of the pasta cooking water.
While the pasta cooks, set a 14-inch saute pan over medium-high heat and add 1 tablespoon of the olive oil, swirl the pan to evenly coat with the oil. Add another tablespoon of the olive oil to the saute pan and season the chicken breast with 2 teaspoons of the Essence and 1/8 teaspoon of the salt. Place the chicken breast in the pan and sear for 3 minutes, turning to ensure even browning. Remove the chicken from the pan and set aside.
Place the remaining tablespoon of olive oil in the saute pan and add the sausage, onions and bell peppers. Saute, stirring occasionally, until the sausage is lightly caramelized and the onions are translucent, about 3 minutes. Add the garlic to the pan and saute for 30 seconds. Add the chicken stock to the pan and scrape with a spoon to remove any browned bits that have formed in the bottom of the pan, about 30 seconds. Add the diced tomatoes, fresh thyme, the remaining tablespoon of Essence and 1/2 teaspoon salt and cook for 2 minutes. Add the skim milk to the pan and cook an additional 2 minutes. Return the shrimp and chicken to the pan, as well as the nearly al dente pasta and the reserved 1 cup of pasta cooking water. Continue to cook the sauce and pasta, stirring occasionally, until the chicken are cooked through, the pasta is al dente and most of the pasta cooking water has evaporated, about 3 minutes. Remove from the heat and add the basil and Parmesan. Toss to combine and serve while hot.