30 minutes before serving, combine tomatoes with next 8 items in a large bowl and reserve at room temperature. Dust fish with flour. Melt butter in a large skillet over medium heat. Add fish and sauté on both sides until lightly browned, but not overcooked. Toss warm pasta with tomato mixture. Add additional salt, if desired. Arrange pasta in mounds on plates, top with fish.
Notes
To seed tomatoes, cut in half widthwise (not across stem end). Place fingers into halves and twist to remove seeds. It’s messy, but fast.