Pig's ear topping ex-PM's potato bites (4,6)
I believe the answer is:
Here is my best explanation:
'potato bites' is the definition.
'pig's ear topping ex-pm's' is the subsidiary indication.
'pig's ear' becomes 'hash'.
'topping' means one lot of letters go next to another.
'ex-pm's' becomes 'browns' (Gordon Brown).