Brush olive oil on one side of the baguette slices and place them on a baking sheet.
Bake in preheated oven to 350ºF (180ºC) until warm. Remove from the oven and set aside.
Mix artichoke with parmesan cheese in a medium size bowl. Stir in onion, mayonnaise and chopped tomato. Season to taste with salt and pepper. Spread mixture on each baguette slice and return to the oven to broil until golden.