What specifically are you looking for? Time periods, places, etc? Human diets are very flexible and varied so it is not the same for every place and every time. Archaeology in general will give you the best answer so searching archaeological sources should help point you in the right direction, but it's still a very broad topic, and talking about what foods were eaten is common to pretty much all archaeology so there's a lot out there.

Just remember, too, that we are limited in what we can say. Bones are more likely to preserve than any plant remains so what we can say is often biased towards animals and away from plants. Burned or charred seeds can preserve too, but not all plants or cooking methods lend themselves to this, and in many places charred remains (or bones, for that matter) do not preserve from the very ancient past, or preserve in only the most exceptional circumstances. Often in these cases we can only make inferences based on what the environment was like at the time of occupation and on analogy with living or historically known groups in similar environments.