Food Aggression Question

I have a 2 Year old Male lab mix that I from a shelter Back when he was 1 year. He was very scrawny and came from a situation where he had to fight other dogs if he wanted to get a proper meal. Hes is very sweet and shy. Hes comes leaps and bounds from when we first got him and he is great with other dogs and even cats.

My dog has no food aggression what so ever towards people. I can reach down and take his food away and he will just back away. But we recently adpoted a kitten. She was 8 weeks when we got her and nows shes 4 months and her and my dog get along famously. Even sleep together.

Getting to my actually question.

My cat is still very curious and wanted to know what the dog was doing when hes eating the cat went up and sniffed his bowl. And my dog growled as a warning and when she got to close barked at her and growled and snipped trying to get her away. After this incident i put the cat in the bedroom while feeding the dog. Or i feed the dog in his kennel if the cat is sleeping.

I know some way of training a dog to be ok with humans and food like a fake hand to simulate someone taking their food and slowly work with them. I have tried using a stuffed cat as the same kind of thing but my dog knows its not a real cat. Hes a acutally afraid of it.

So my question is has anyone else had problems with this and what is a good way to help him understand that he doesnt have to fight for his food anymore without putting my cat or my dog in danger?