Bring 4 quarts of water with 2 tablespoons salt to a boil in a large pot and cook dry penne pasta to desired doneness per package directions. (Only 2.8 quarts - 2.5 liters - of water are required, but with the smaller amount of water, it would take longer for the water to return to a boil once the pasta is added.).
Meanwhile, precook broccoli florets and carrots. If boiling in water, boil for 3-5 minutes and check for doneness with fork. Otherwise, vegetables can be steamed. Once cooked, transfer vegetables to ice water to halt cooking and preserve bright color, then drain. Set aside until step 4.
In a large heavy skillet, heat the olive oil 1 minute or until hot and saute the onion and garlic until lightly golden, about 3 minutes.
Add the vegetables and saute until the peppers are soft, about 2 minutes.
Deglaze with the beef broth, if using, or just a splash (1 fluid ounce) of dry white wine.
Add the drained penne noodles and basil and season to taste.
Toss well and serve immediately with some freshly grated Parmesan or Grana di Padano cheese on the side.