1. Bring a pot of salted water to a boil and cook the penne pasta to just before al dente. Reserve ¼ cup of pasta water, drain and set aside.
2. Meanwhile, heat 2 tablespoons of butter and 2 tablespoons of olive oil in a large skillet over medium heat.
3. Add the onion and cook until translucent, about 1-2 minutes.
4. Stir in carrots, broccoli, red bell pepper, asparagus, minced garlic, one at a time, stirring for 2 minutes before adding the next ingredient
5. Season vegetables with a pinch of salt and pepper, then transfer to a plate and set aside.
6. To the skillet, add a tablespoon of butter, 3/4 cup chicken broth, ¼ cup lemon juice and ¼ of cup pasta water. Bring to a boil and simmer until slightly reduced; 2-3 minutes.
7. Stir in the pasta and continue to simmer until sauce is reduced by half; 3-4 minutes. Stir in vegetables and season with salt and pepper as desired.
8. Top with fresh grated Parmesan cheese (optional) and serve immediately. Garnish with fresh minced parsley and serve with lemon wedges if desired.