Toss the cauliflower florets with 2 tablespoons of oil on a baking tray. Season with salt and pepper and roast in the oven for 15-20 minutes, until they start to bronze. A little charring will add depth and flavour.
Meanwhile, make the soup. Heat the remaining oil in a medium/large saucepan, add the onion, celery and garlic and gently sauté, keeping the heat low. Add the thyme leaves and prepared cauliflower stalk. Season with salt and pepper.
Pour in the Almond M*lk and vegetable stock. Heat gently up to smoking point (when you start to see some steam but before the boil) – a rapid boil can split the milk.
Once the cauliflower is roasted, add it to the saucepan, and continue to cook gently for 5 minutes. Turn off the oven.
Scatter the almonds onto a clean baking tray and dry-roast in the residual heat of the oven for 3-4 minutes, then coarsely chop.
Remove the soup from the heat and allow to cool slightly, before transferring to a jug blender and blending until totally smooth – the smoother the better. Taste and adjust the seasoning accordingly.
Serve the soup in warmed bowls, garnished with a twist of black pepper, some fresh thyme leaves, the chopped roasted almonds and a generous squeeze of lemon juice to make everything sing.