Heat a medium pan on the stove. Add 3 tablespoons of olive oil and the onion and garlic and sweat till starting to soften (5-8 minutes)
Add the thyme, potatoes and roughly chopped celery. Continue to cook for 5 minutes.
Add the stock and simmer on low for about 20 minutes. Add salt and pepper and blend till very smooth ( you could use a hand mixer or processor.)
To make the topping.
Heat a non stick fry-pan till very hot. Add the oil and the Chorizo and sauté till the chorizo starts to release oil and get caramelized. Then add the barley ( or nuts) and toss till starting to colour slightly and get crisp. You can mop up some of the chorizo oil in the pan if you like but I think it gives the sprinkly bits lots of flavour. Sprinkle in the parley and stir. Keep warm
When you put soup into each of the bowls, sprinkle with the chorizo and barley and then crumble some of the feta and serve.