Trim rough outer skin of celeriac, julienne using Robot Coupe.
Brown the butter in a large pan over high heat. Add celeriac and cook on medium heat for at least 2 hours, stirring often, until soft and moisture has evaporated.
Toast coriander and peppercorns, then crush. Heat milk and cream to 80°C, add thyme, spices, and optional smoked water. Infuse for 1 hour, strain and set aside.
Check celeriac with sous chef. Add half the infused milk and reheat gently.
Blend in Thermomix on speed 8 for 3-5 mins. Gradually add remaining milk to achieve a silky, pipeable texture.
Season to taste.
Carrot Purée
Combine carrots, water, butter, and salt in a saucepan. Bring to a boil, then reduce to low and cover. Cook for 20 mins until tender.
Transfer carrots to blender with a slotted spoon. Add ½ cup cooking liquid and 1 tbsp lemon juice.
Blend until smooth, adding more liquid as needed. Season with salt and adjust lemon juice to taste.
Courgette Skin & Herb Purée
Trim courgettes, keeping only the green skin.
Heat oil in a pan, add chopped skin, cook on high for 5-10 mins.
Strip thick basil stems, chop the rest. Add basil, chives, salt, and garlic. Sweat for 5 more mins.
Blend in Thermomix on speed 8 for 3 mins. Add up to 50 ml water if needed.
Season to taste and check with senior chef. Chill quickly over ice.
To serve: mix 1 kg puree with 500 g ricotta. Reserve some plain puree for vegan use.
Cauliflower Purée
Heat butter and oil in a large pan over high heat. Add cauliflower and cover with cartouche. Sweat for 20 mins.
Remove cartouche and continue cooking until deeply golden and very soft.
Add cream, parmesan, and vinegar. Simmer, then remove from heat.
Divide between Thermomix jugs and blend on speed 8 for 5 mins. Add milk as needed to achieve a silky, spoonable texture (should hold a clam).