Pasta with Garden Tomatoes and Fresh Mozzarella

Toss mozzarella and salt together, and set aside. Fill a medium stockpot with water and bring to a boil. Heat the oil and butter in a large sauté pan over medium-high heat. Add the onion and garlic, reduce the heat to medium-low and cook, stirring occasionally, until the onion is very tender — about 10 minutes Cook the pasta in the boiling water until al dente. Add the tomatoes to the cooked onions, and increase the heat to medium-high. Continue to cook, stirring occasionally, until just tender — about 5 minutes Drain the pasta, and toss into the tomato-onion mixture to evenly coat. Remove from the heat and stir in the salted mozzarella and 1/4 cup Romano cheese. Transfer to a large platter and garnish with fresh basil leaves and remaining 1/2 cup cheese. Serve immediately.