"Double-ended ingredient cards" is a little awkward and is worth explanation. Something like this would provide clarity: "Each card has two ingredients. When playing, orient the ingredient you wish to use so the letter reads correctly when facing you."
"On your turn, you can ..." State clearly that players can take as many actions as they wish, provided they have enough cards in their hand.
"The value of the check's total ..." Is an important rule and should not be in parentheses.
At least one example of a Guest Check that requires more than one burger would be helpful. Do any of them require specific ingredients?