1In 12-inch skillet, heat oil over medium-high heat. Cook tomatoes and shallot in oil 4 minutes, stirring frequently, until tomatoes begin to burst and skins are blistered. Gently press half of tomatoes with back of spoon to release juices.
2Stir in wine, chopped thyme, salt and 1/2 teaspoon pepper, scraping bottom of pan to loosen browned bits. Add butter; simmer 5 minutes.
3In serving dish, toss mozzarella with warm tomatoes. Garnish with thyme sprigs and additional pepper.