For sauce; combine all the ingredients and mix well, allow to stand.
Remove crusts from bread and chop finely, about 5mm x 5mm. Cut each slice into 4 squares.
Place squares between layers of plastic wrap and use a rolling pin to roll flat.
Place squares in a mini muffin tin and brush with olive oil. Toss crusts with remaining olive oil and place on a baking sheet. Bake bread and crusts at 160°C until crisp, roughly 10 minutes. Stand to cool.
Place tomatoes in a bowl and add Bloody Mary sauce. Stand for 5 minutes.
Add crouton crusts and mix well. Spoon into bread cups, sprinkle with parmesan and serve immediately.