Turn the top broiler on in your oven.

Slice the red bell peppers, tomatoes and onion in half. Remove the seeds and stems from the bell peppers, the stems from the tomatoes and the outer peel from the onion.

Place the vegetables on a baking tray and drizzle with olive oil and season with salt and pepper. Rub the oil and seasoning on both sides of the veggies.

Roast for 25-30 minutes, or until the top side has a nice black char on it.

Transfer the bell pepper to a glass bowl and cover with plastic wrap for about 20 minutes, to steam.

When the other veggies are cool enough to handle, remove their skins and transfer to your blender.

Add the tomato paste, balsamic vinegar, dried basil and water (or stock) to your blender.

Blend everything on high until smooth.

Before serving, top with optional garnish.