First of all, bibimbap I believe is only served in C, not in Y for regional flights. For the two routes you've mentioned I have no experience so can't comment but I have flown a lot of other regional flights in Asia in C over the past few months. Up until this month my experience was that they have a choice of three dishes, with one being bibimbap. However for redeye flights no bibimbap. For morning flights I have no experience so don't know what they offer but assume it's a different menu from lunch or dinner. As of this month they have started offering bibimbap on their redeye flights and changed to nakji (octopus) bibimbap for the evening flights. I would have tried the nakji bibimbap on my last flight but they ran out as the C cabin was full with all other passengers being Korean and ordering the bibimbap. I have a flight this evening so will order it straight away this time when I get my menu. However in looking at what the others got it doesn't look as appetizing to me as regular bibimbap being they only put cucumber slices and bean sprouts in it whereas the regular bibimbap has a bigger selection of vegetables. One word of warning about the bibimbap is to go easy on the red pepper paste as the stuff Asiana uses is more pasty without as much liquid as what you'd normally get in a restaurant and so seems spicier for the same amount. I made a mistake the first time of putting in too much.