Finely blend the blanched almonds. Put the milk in a pan with 200 ml (7 fl oz) water and add the almonds. Heat to 55°C (131°F) and then cover and put in the fridge overnight. Strain the almond milk into a heavy-based saucepan and add the salt, linseed oil, gellan and iota. Heat to 84°C (183°F), stirring continuously. Strain onto a tray and refrigerate for about 30 minutes to set. Purée until smooth and then keep chilled.