Put:
In a roasting pan and cook in the oven until soft.
I removed the onion skins, and squeeze the pulp of the garlic out, and the tomatoes skin just peels off easily (I leave seeds in)
Toss everything into a sauce pan over a low heat and blitz it with a stick mixer. Doesn’t usually need stock. Then I just season it.
Depends on how we feel - might be salt and pepper, paprika, basil if you like.
I’ve even tossed a chilli in the roast pan as well.