Possible Clues:

• Bung cheese round top of bun
• Carrot and head of broccoli smothered in cheese
• Palm grease
• Grease, so to speak
• Oil the palm (of)
• Dishonestly persuade
• Payola, e.g
• Corrupt European leaves tropical disease reduced by last quarter
• Pay for political favors
• Bit of butter in cheese making grease