Add 1 tablespoon olive oil to a large skillet over medium-high heat.

Place pork medallions between two sheets of plastic wrap or wax paper. Lightly pound to about ¼-inch thickness.

Remove the top sheet and season both sides of the pork with garlic powder, salt, and black pepper.

Add the pork to the hot skillet and sear for 4–5 minutes or until golden and easily released from the pan. Flip and cook another 3–4 minutes. Transfer to a plate and set aside.

Note: The pork will finish cooking later.

Reduce heat to medium. Add butter, mushrooms, and remaining olive oil to the skillet. Stir in rosemary and season lightly with salt and pepper. Cook 4–5 minutes, or until browned and softened.

Pour in chicken broth and deglaze the skillet, scraping up browned bits for extra flavor.

Stir cornstarch (or arrowroot) with a splash of warm broth from the skillet until smooth. Add this slurry back into the pan and stir until the gravy begins to thicken.

Return the pork and any accumulated juices to the skillet. Cover and simmer over medium-low for 2–3 minutes or until heated through.

Garnish with fresh parsley and serve immediately.