In a separate bowl, mix the olive oil and harissa paste together. Toss into the veggies.
Taste and season with salt and pepper. Let sit to let the flavours marry.
Cut up the baguette into bite size slices and lay out on a baking sheet.
Spoon some of the topping onto each slice. (about 2-3 tbsp depending on the size of the slices)
Sprinkle some of the grated cheese onto each slice. (about 1 tbsp)
Place the baking sheet into the oven and bake for about 3-5 minutes, until the cheese has started to melt into a gooey topping.
Serve.
This recipe makes about 2 cups, depending on the size of the tomatoes you are using.
This amount will easily make about 16-18 crostini, or a bit more. For an appetizer, I count on 3 pieces per person.
For a meal where you would probably eat around 5 slices, this will easily serve 4 people.