Put the onion in the mixing bowl. Chop 5 sec / speed 5.
Add oregano leaves and olive oil. Sauté 3 min / 120° / speed 1.
Add red bell peppers cut in quarters, the canned tomatoes and vegetable stock. Mix 5 sec / speed 5 and cook 20 min / 100° / speed 1.
Add feta cheese and pepper. Mix 1 min / speed 10.
Pour the boiling soup in mason jars, close the lid, let cool and refrigerate.
Serve this velouté in verrines as an aperitif or in bowls for starters. Just before serving, add a bit of balsamic vinegar and possibly a few extra pieces of feta cheese.
Notes
This soup can be stored for 3 weeks in the fridge.
This soup is also very good served hot, without balsamic.