Remove pork from fridge to reach room temperature, preheat oven to 400°F, and season pork with salt, pepper, garlic powder, and herbs.
Heat olive oil in an oven-safe skillet over medium-high heat and sear pork on all sides for 2-3 minutes until a golden crust forms.
Transfer skillet to oven and roast for 20 minutes until internal temperature reaches 140°F.
Remove pork and let rest, then using the same skillet over medium heat, cook chopped shallot for 2 minutes.
Add blueberries, balsamic vinegar, honey, and broth, cook 5-8 minutes until berries pop and release juices, add herbs and cornstarch mixture, simmer until thickened, and stir in butter if using.
Slice pork and serve with blueberry sauce drizzled over top.
