This is from the Standard Course Book of HSK5, section 19.
Please help me understand the literal translation of this: 盖锅前须放进一些温水，预防糊底。
I don't understand the 盖锅前须 and 糊：
盖锅前须(?)放进(to put in)一些(some or a little)温水(warm water)，预防(to prevent)糊(?)底(bottom)
盖：does it mean to cover?
锅：does it mean pan?
前：does it mean front?
须：does it mean must or have to?
Something like, you must cover the pan front? Or what else?
糊：rice gruel? To prevent rice gruel from bottom? I don't get the meaning.