For an event this weekend, I'll be making Spanish tortilla rounds topped with a sundried tomato/red pepper/manchego pesto. I want to top each tortilla round with a little dollop of pesto as part of the garnish, but I'm concerned about it separating during the event, and I don't want the platter to end up with splotches of red oil under each round. Any thoughts for preventing this? Maybe top with a little creme fraiche first, then the pesto to keep it contained? I've had the jar on the counter and have been draining the oil as it rises to the surface, but not sure that'll do the trick.