Preheat the oven to 325ºF. Then place a large cast iron skillet, (9"-10") over high heat.

When the pan is hot but not smoking, add the avocado oil and swirl to coat the bottom of the pan.

Place the roast in the pan and sear both sides until they're golden brown, about 3-5 minutes per side.

While the roast is searing, mash the butter, garlic, rosemary, sea salt, and pepper together in a small bowl.

When the roast has been seared, turn off the heat. Then spread the garlic herb butter as evenly as you can across the top and down the sides a bit.

Pour the chicken stock into the bottom of the pan and place the skillet in the oven.

Cook until the pork roast is done, 50-60 minutes. An instant read thermometer will read 145ºF when the pork roast is done.

When the pork is done, remove the skillet from the oven. Carefully transfer the roast to a plate, cover and let rest for 5-10 minutes.

While the roast rests, mix the cornstarch together with water until smooth. Place the cast iron skillet on the stove top over medium high heat and drizzle just enough of the cornstarch mixture into the simmering juices to thicken them to your liking. Stir constantly as you add the starch mixture.

Add more chicken broth if desired to make more gravy and season to taste with sea salt and black pepper.

Cut the pork roast into ½"-1" slices and serve them with the gravy and your choice of side dishes.