Chop up pistachio nuts.
Cut chicken into thin slices and season well with sea salt and pepper. Set aside.
Cut off bottom inch or so of asparagus, if not already trimmed, then cut into thirds.
In a stock pot, over medium-high heat, cook the asparagus in salted boiling water; about 4-5 minutes. Remove the asparagus, but retain the stock pot water for the pasta.
Heat cast iron skillet on high. After five or so minutes add two tablespoons olive oil, let heat and add the chicken and cook until done. Meanwhile, add penne to boiling stock water and cook until al dente. When pasta is done drain into colander.
Once chicken is done, remove from skillet and wrap lightly in foil. Add butter to skillet and saute garlic until it starts to brown.
Add wine and deglaze skillet. Add the asparagus and pepper and cook about a minute. Reduce heat to medium and add heavy cream and half and half. Season with salt and simmer for 2-3 minutes.
Add pasta back to empty stock pot. Stir in asparagus mixture over low heat. Add parmigiano-reggiano and continue stirring until melted and well combined. Mix in half of the pistachios.
Serve and garnish with remaining pistachio nuts and a little parmigiano-reggiano.