Preheat oven to 425 degrees.
Slice baguettes into 18 equal pieces.
Combine in a small bowl, mayonnaise, parmesan, onion, garlic, pepper and basil.
Spread mixture evenly on to crostini.
Bake or 10-15 minutes until golden brown.
Remove from oven and top with tomato.
Garnish with a sprinkle of parmesan cheese and parsley (optional).
Serve warm. Enjoy!!