Step 1 of 4

Soften the onion and carrot

Heat the oil in a large pot over a medium heat and cook the onions and carrots with a teaspoon of the salt for 10 minutes, until soft and just beginning to color at the edges. Add the garlic and cook for a minute more.

— Salting at this stage draws water out of the onion so it softens rather than fries, which is what you want under a soup.