I think you are right it’s chicken breast rolled with different layers then sliced on a platter the green layer is spinach. I did plates like that when I had friends around I probably drizzled it with garlic butter to keep it moist.
It was a breast of chicken flattened out and laid on top of streaky bacon rashers and then topped with fennel, then skinless red pepper and I just can’t remember what the green layer was …. Might have been spinach. Then it was rolled up, placed in foil and put in the oven for not sure how long. When it was cooked it was left to go cold, then sliced up and put on a platter. It looked very good. Shame I can’t remember the final details. 🤷♀️
This is such a long shot but you never know! In the 90s I used to do finger buffets. One of my favourite items was rainbow chicken. However after I moved 10 years ago I possibly threw several cookery books away including the one that contained the recipe for Rainbow Chicken. I think the book was called party food or something similar. It was one of a series in quite a slim rectangular shape, by different authors. Has anyone got it??