Pre-heat your oven to 180c (350f).
While the oven is heating up, cut the onions and carrots into rough, large chunks.
Put them in a bowl and add the salt, pepper, and extra virgin olive oil.
Mix to coat the vegetables in the oil and spices.
Pour the vegetables out onto a baking sheet and set the bowl aside for use later. Optionally, you can add a protective layer of aluminum foil to make cleanup easier.
Bake for 30 minutes.
While the onions and carrots are in the oven, cut the bell peppers into rough, large chunks.
Add them to the mixing bowl. There should be enough oil and spice to lightly coat the peppers.
After the onions and carrots have baked for 30 minutes, remove them from the oven. Add the peppers to the baking sheet and mix them in.
Bake for another 30 minutes.
Remove from the oven and let cool for 5 minutes.