I don't mean to put a dampner on this recipe, but I have been cooking in general for over 30 years now and I have never known onions to disintegrate in anything.

The recipe calls for very finely chopped onions, and onions will most certainly disintigrate if finely chopped. I usually cook my curries in the traditional slow cooked method (no base sauces, etc.), starting with very finely chopped onions (we're talking a couple mm cube), and the resulting sauce is of a good thick texture (doesn't need other thickening agents like yoghurt, etc.) and you'll not find any bits of onion.