Our dog takes delight in eating on an arbitrary and seemingly random schedule. After carefully observing her behaviour over time, a pattern emerges.
One factor that can help is the “Cat Incentive Plan”. There’s two options here that for simplicity I will call Blue and Black. In the case of Black, the presence of a black cat will force the dog to eat (or pretend to) whatever is presented in her dish. In the case of Blue, the presence of a blue cat will encourage the dog to invite the cat over to partake of the meal, thereby making plate-clearing a collaborative effort.
Hope this helps describe this odd behaviour.