Once sauteed, add the onion and garlic to a slow cooker over high heat ... When ready to serve the soup, garnish with extra cilantro, low-fat sour cream or other favorite toppings.
As the soup will be extremely hot, there should be no need to reheat once the milk or cream is added. However, you can always return the pot to the slow cooker for an extra 10–15 minutes on high ...
For a thicker soup, add 2–3 tablespoons cornflour mixed with a little water at the same time as the milk or cream. You will need a slow cooker that holds at least 4 litres/7 pints for this recipe.