*If* it's right, it's tenuous but it's the RTE. I can only presume that they think the words are homophones somewhere with an accent that renders them so...
harden into a solid or semi-solid state.
"cook for a further thirty-five minutes until the filling has set"
synonyms: solidify, harden, become solid, become hard, stiffen, thicken, gel; More
cake, congeal, coagulate, clot;
freeze, crystallize;
raregelatinize
Many thanks to all and I will go with asset. RTE seem to think we have to be put through hoops on at least one every week.
ps: I see RTE has accepted an incomplete answer to 16d on No 45 which couldn't be completed in any event because 'rosebud' got it wrong. Not only accepted but has agreed to pay prizes!! Where do we go from here?
Yes, I agree with Lie-in King. Ever since there was clue that was based on debt and death being homophones I often say my possible solutions to RTE aloud using the strongest Irish accent I can manage