Avocado-and-onion soup

This soup looks "bizzarro", and has a "bizzarro" texture, but it tastes fine. The Internet is solely to blame for this attempt to use up overdue avocados by making soup out of them.

The beginning is standard: sautee onions and garlic in butter, add flour, and after a while pour in stock and simmer to soften up the vegetables. The weird part is adding puréed avocados and lime juice. Throwing avocado into a blender results in guacamole, so I used some stock to thin it out. My soup was a tad too sour, so in the amounts below I call for a third of the limes that I used.

- 3 cups of stock (of which some can be used in the blender)
- 2 avocados, puréed
- 2 oz butter
- 2 onions, chopped
- 2 garlic cloves
- juice of 1 lime
- 1/2 cup flour