Preheat the oven to 200 C.
Prep your veg: 1) Halve the onions and chop them up into thick wedges (about 6 wedges from each onion). 2) Halve the red peppers and remove the seeds and inner white membrane. 3) Chop the tomatoes into the same size as the onions. 4) Halve the zucchini and carrot lengthwise and chop them into batons about the size of your finger. 5) Leave the banana peppers whole. 6) Leave the garlic cloves unpeeled.
Add your prepped veg to a baking tray and toss them with olive oil and salt. Use your hands to get them evenly coated. (tip: pop the garlic cloves underneath the peppers - this will help them steam and not burn).
Lay them out in an even layer without overlaps. Use two trays if necessary.
Bake for 50-55 mins until they are charred and blistered. Set aside to cool slightly. Once cool enough to handle, peel away the papery skins on the red peppers and discard. Also do the same with the banana peppers. Tear open the banana peppers with your fingers and remove and discard the seeds. Squeeze out the garlic from their skins.
Add everything to a blender and blend to a smooth purée. Add the Worcestershire sauce, basil leaves (or pesto) and oregano. Blend again. You might have to do this in batches. Taste and adjust seasoning.
Decant into jars and refrigerate or freeze. Can be kept refrigerated for up to a week or frozen for up to 3 months.