If you have a fertile garden soil that has organic matter (e.g. added compost) and a balanced pH (not too acidic or alkaline), you should be able to add food wastes in moderate amounts and let the soil ecosystem take care of it. If the soil is low in organic matter, there might not be enough life in the soil to rapidly breakdown the influx of protein into nitrogen. If the pH is too high or low, that would also affect the ability of the soil critters to respond rapidly.
A key component to this is mixing the wastes in well so that they don't smell and the neighborhood varmits don't have a chance to get a mouthful of the stuff. So that's the other part of this. Don't do it if it can be turned in or soaked in. I have done this with sour milk, raw eggs and hard boiled eggs. I have never noticed a smell from the decomposition process. On the other hand, when I use commercial fish fertilizer, THAT smells!