Clue: Extremely reclusive Irish writer expresses delight (7)
Answer: REJOICE
Explanation: Definition: delight
R[eclusiv]E + homophone of [James] Joyce. Nutmeg has already commented on the Guardian site that "expresses" here should be "expressed". I was worried about rejoice=delight, but I think it works as a verb – "delight in" = "rejoice in"