Slice chicken breasts into bite-sized chunks and season with salt, pepper, and onion powder. Let sit on a shallow plate while you prepare the asparagus.
Wash and trim the ends of the asparagus, blanch them in boiling water for 2 minutes, then soak them in ice water to stop the cooking. Drain and set aside.
Melt half the butter (¼ cup) with olive oil in a large cast-iron skillet over medium heat. Gently stir-fry the chicken bites on all sides until golden brown. Lower the temperature, and add one teaspoon of minced garlic and Italian seasoning. Stir and cook the chicken bites for one minute more until the garlic is fragrant. Remove the chicken bites from the skillet and set aside.
In the same skillet over medium-high, add the remaining teaspoon of minced garlic, then deglaze with chicken broth (or wine). Bring to a simmer and allow to reduce to half the volume. Add the remaining ¼ cup butter, lemon juice, hot sauce, and parsley. Give a quick stir to combine.
Add the blanched asparagus and toss for 2 minutes to cook it up. Push asparagus on the side, add the sauteed chicken bites back to the pan, and stir for another minute to reheat. Garnish with more parsley, crushed chili pepper, and lemon slices, and serve.
