Success. The recipe calls for a bit more time than the standard Throw Everything Into A Pot and Wait For An Hour soups, but it was well worth it.
I roasted the potatoes, caramelized the onions and sauteed the veggies a day ahead. Simmered everything together for 20 minutes and then left it in the fridge. Last minute I did the food processing and curried apples and voila! A delicious, plan-approved, vegetarian and vegan soup. Delish.