Pork Osso Buco

Season pork shank with salt and pepper.

Heat olive oil and butter in a heavy pot over high heat. Sear pork shanks in hot butter-oil mixture until browned, 3 to 4 minutes per side. Transfer to a plate and set aside.

Cook and stir onion, celery, carrot, and salt in the same pot over medium heat until onion turns translucent. Add tomato paste; cook and stir until tomato starts to caramelize, about 2 minutes. Sprinkle in flour; stir for 2 minutes. Pour in wine, increase heat to medium-high, and simmer until sauce reduces slightly.