Combine first four ingredients in a medium bowl. Let stand at room temperature 1-2 hours stirring occasionally.
Fluff ricotta with a fork. Thin to creamy consistency with whipping cream. Season with pepper and nutmeg. Mix in Fontina and Mozzarella. Let stand at room temperature while cooking pasta.
Drain most of the liquid from tomatoes leaving just enough to keep moist. add pasta to a large amount of boiling salted water, stirring to prevent sticking. Cook until just tender but still firm to bite. Drain well. Place in a heated bowl. Mix in olive oil. Add cheese mixture and toss until cheese begins to melt. Spoon tomato mixture over top; toss mixture at the table. Sprinkle each serving with Parmesan.