In large, nonstick skillet over medium heat, melt 1 T butter. Cook tomatoes in hot butter, 3 to 5 minutes, until tender. Remove tomatoes, set aside. Cook onions in remaining 1 T butter, 3 to 5 minutes, until tender. Add rice; cook 2 to 3 minutes stirring frequently. Add wine; stir until absorbed. Increase heat to medium-high; stir in 1 cup broth.
Cook, uncovered, until broth is absorbed, stirring constantly. Continue stirring, adding remaining 1 cup broth & water, allowing each cup to be absorbed before adding another, until rice tender & mixture has creamy consistency. (Total cooking time will be about 25 to 30 minutes.).
Stir in cheese, milk & reserved tomatoes; cook until heated through. Add salt & pepper to taste. Serve immediately.