Clue: Cut power after city church is besieged by angry mob (4,4)
Answer: LAMB CHOP
Explanation: Definition: Cut
 P(symbol for "power" in physics) **placed after**(after) { LA(abbrev. for Los Angeles, the American city) + [ CH(abbrev. for "church") **contained in**(is besieged by) **anagram of**(angry) MOB] }.
Defn: A thick … of meat of lamb, around and often including a rib.