Remove leaves from cauliflower head, core, and cut into large, bite-sized florets. Halve and peel onion. Slice halves into thin strips. Mince garlic. Stem and mince parsley. Finely chop pistachios. Pat pork chops dry, and season both sides with ¼ tsp. salt and ¼ tsp. pepper.
Sear the Cauliflower
Heat 1 Tbsp. olive oil in a medium non-stick pan over medium-high heat. Add cauliflower florets to hot pan and stir often until lightly charred, 3-4 minutes. Remove from burner and transfer to one side of prepared baking sheet. Spread into a single layer on their side and roast 5 minutes. Cauliflower will finish cooking in a later step. Reserve pan and wipe clean.
Cook Pork Chops and Finish Cauliflower
Return pan used to sear cauliflower to medium-high heat. Add 1 tsp. olive oil and pork chop to hot pan. Sear undisturbed until browned, 3-4 minutes. Transfer empty side of baking sheet, seared side up. Reserve pan; no need to wipe clean. Roast until cauliflower is tender and pork reaches a minimum internal temperature of 145 degrees, 6-8 minutes. While pork and cauliflower roast, cook onions.
Caramelize the Onions
Return pan used to sear chops to medium-high heat. Add 1 tsp. olive oil and onions to hot pan. Stir often until caramelized, 6-8 minutes. Remove pan from burner.
Crust the Pork
Spread goat cheese on pork chops. Sprinkle with pistachios and remaining parsley. Rest 3-5 minutes.