From times to times, I make this soup that consists of 90% onions and 10% green pepper/garlic/white cabbage/carrots. Not matter how much water I add to it, it always ends up quite thick after blending. I own 2 different (Though not particularly priced) hand blenders and normally try to blend the onion stock with both and sieve it, however after blending the soup, there is a thick layer with a paste-like consistency in the sieve that no matter how much I try to scrape using a soup, it just won't strain through. Could I be undercooking the stock?
My method is normally: 1.5kg - 2kg of onions, 1 green pepper, 2 carrots, 1 piece of cabage same weight as carrots. I put it all in the pressure cooker and boil it for about 20 - 40 mins after it peaks pressure in a low heat. On another note, I also notice this puree/stock/soup never really gets very sweet as I would hope it to. Perhaps I need to simmer it longer so as to help the onion and other veg to break?