Turn up in Mongolian hut, finding dairy product (6)
I believe the answer is:
yogurt
'dairy product' is the definition.
(I know that yogurt is a type of fermented milk product)
'turn up in mongolian hut' is the wordplay.
'turn' becomes 'go' (a person's move in a board game).
'up' says the letters should be written backwards (in down clue: letters go upwards).
'in' is an insertion indicator.
'mongolian hut' becomes 'yurt' (type of hut used in Mongolia).
'go' written backwards gives 'og'.
'og' placed within 'yurt' is 'YOGURT'.
'finding' acts as a link.
(Other definitions for yogurt that I've seen before include "Fermented milk product" , "Food prepared from thickened milk" , "healthy breakfast" , "dessert?" , "Cultured fare" .)