Peel and finely slice the shallots. Break the cauliflower into even florets 1.5cm wide; chop the stalks and any leaves into 1cm pieces. Prepare a bowl big enough for the celeriac, fill ⅔ with water & a squeeze of lemon juice. Chop the celeriac into 1cm pieces and store in the lemon water until ready to use
Heat the oil over low heat in a large lidded saucepan. Gently sweat the shallots for around 10 mins over low heat, until soft and transparent. Partially cover pan; stir regularly. Do not allow to brown or the soup colour will be spoiled
Add garlic, cauliflower & whole thyme sprigs to the pan and stir. Drain the celeriac well and stir in. Continue to sweat everything, stirring, for 5-10 mins – again, do not allow to brown
Add the bay leaf, almond milk and water for cooking. Bring to the boil, stir once, cover and simmer gently until the cauliflower is very tender, probably around 15 mins. Allow to cool until warm, not hot
Remove the herbs. Blend the soup. You may need to do this in batches. Add more milk as needed, up to the amount specified in the recipe. Too much and the flatter almond milk flavour will dominate, detracting from the sweet cauliflower/shallot notes
Taste. It should have a creamy, slightly sweet flavour. Season with salt or miso; do not over-salt