there .......... butter and cheese in the sandwich

is -- are

is , because all food is uncountable nouns and we deal with it as singular nouns

طب و cheese and butter

Are
I asked the English supervisor

are is the correct answer

الاحابة الصحيحة هي are لانه اذا كانت cheese فقط او butter فقط لاخترنا is اما وانه قد وجدت and فهناك اضافة والاضافة تعني الجمع والدليل على ذلك هو ان تجيب على هذا السؤال , كم صنف من الاطعمه موجود في سؤالك؟والاجابه هي اثنان

Use ARE because though u r dealing with uncountable nouns here yet they r two different kinds of food cheese and butter two things that's why it's more accurate to use are