My head chef had me make a thickened creme anglaise/creme pat with 1200ml cream, 180gm sweetened egg yolk, 200g sugar, vanilla pods, and a couple-ish tablespoons of cornflour. She said it thickened enough to pipe in the UK, but New Zealand cream isn't as thick as UK cream so we had to add the cornflour. I made this the other day and it worked out fine but I made it again today and I think it's split, when I poured it into the tray to cool it down there was a greasy yellow stuff on the top and after it had been in the blast chiller it had set like butter on top, it looks like the fat from cream/butter I guess. My head chef is the owner and hates any wastage so I was wondering if there was any way to fix it so I don't get in trouble for screwing up? I read somewhere using an immersion blender on it could work?