Poodles are often super at self-regulating. (Sometimes a little too super!!) Maybe just keep doing what you're doing, but lift up his lunch bowl after 20 minutes. If he continues ignoring it, scrap that midday meal altogether (being sure to monitor his energy levels and weight).
You could also try shifting that lunch portion to his breakfast or dinner and see what happens. Maybe he still needs the nourishment, but it's just the timing that's making him not want to eat a midday meal.
I think Peggy was around 6 months when we switched to two meals a day: first breakfast and dinner, and then lunch and dinner since she went on a breakfast strike a couple of months ago.
I keep a daily log of all her meal times and portion sizes. It's been very helpful.