I recently had the same problem to solve in windy Curacao
. A friend was supposed to come help, but he overslept. A year earlier singlehanded in (much calmer) Caranero Venezuela
I made a pig's arse of it and being the anal retentive I am; later that day I went over in my mind how I would improve the next occassion should it be necessary. Note: I have a centre cockpit
I unflured the genoa and tied off the roller line at bow cleat. I then undid the tack shackle and loosened the halyard about four feet tying it off at centre cleat. Connected tack shackle to anchor
chain then released/ tied off halyard in concecutive three feet lengths which one can quite quickly flake, I used a large boat hook to restrain each fold. Around half way down, with the lower folds reasonable secure, one is able to release the halyard and finishing flaking, with the help if necessary of the boathook.
When finally fully flaked I roll it up to the tack shackle undo and tied.