Place pork in large bowl. Add garlic, 1/4 teaspoon of the sea salt, pepper and vinegar; toss to coat well. Heat 1 tablespoon of the oil in large skillet on high heat. Add pork; brown on all sides. Remove pork from skillet. Set aside.
Heat remaining 2 tablespoons oil in same skillet until shimmering. Add broccolini; stir-fry until tender crisp, about 5 minutes. Stir in XO Sauce, tossing to coat broccolini. Return pork to pan; cook and stir until heated through.
Meanwhile, for the Polenta, bring stock, milk and remaining 1 teaspoon of the sea salt to boil in large saucepan. Whisking constantly, add polenta in thin stream. Reduce heat to low; stirring constantly, simmer 3 to 4 minutes or until thickened. Remove from heat. Stir in cheese and butter. Serve pork and broccolini over Polenta with additional XO Sauce. Sprinkle with additional Parmesan cheese.
Test Kitchen Tips:
• XO sauce, the iconic condiment, was first created in Hong Kong. Meant to impress, it is known to be a luxury blend typically made with dried shrimp and scallops, Chinese dry-cured ham, garlic and various chiles. The ingredients, combined in a base of oil, create an intense sweet, salty, rich umami flavor.