Slice tops off tomatoes; reserve. Use a small spoon or melon baller to scoop out pulp; discard pulp. Invert tomatoes onto paper towels, cover with plastic wrap and refrigerate until ready to fill
Squeeze as much moisture as possible from broccoli and pat dry with paper towels. Place in bowl of a food processor and add mayonnaise, sour cream, Parmesan and crushed red pepper. Pulse a few times to thoroughly mix, but do not completely puree. Season with salt and pepper. Refrigerate until ready to serve.
Spoon 1 tsp. filling into each tomato, mounding filling slightly. Set tops on filling. Serve chilled or at room temperature.