Reddit reviews Cookery and Dining in Imperial Rome

In the Shadow of Slavery: Africa’s Botanical Legacy in the Atlantic World does a great job of showing how many foods we take for granted today actually came from Africa and were connected to the slave trade in the Americas.

The Taste of Conquest: The Rise and Fall of the Three Great Cities of Spice is a book I'm reading now about the history and geography of spice and the spice trades.

For a nonacademic resource, Michael Pollan's The Botany of Desire is an excellent plants'-eye approach to four important crops. Although only two of them (apples, potatoes) are food, the approach is really engaging and thought-provoking. Pollan's more famous book, The Omnivore's Dilemma is good, but focuses primarily on corn.

Similarly non-academic but smart, Deborah Valenze's Milk: A Local and Global History presents an interesting history of milk, how colonization and different breeds of cows influenced cultures of milk, etc.

Since you are interested in cuisines and how they changed, I also recommend:

Stirring the Pot: A History of African Cuisine by James McCann

Cookery and Dining in Ancient Rome by Apicus.

One of the best and most dramatic works I can recommend is The Ghosts of Cannae: Hannibal and the Darkest Hour of the Roman Republic, by Robert L. O'Connell. The battle of Cannae was a turning point for Rome, and O'Connell captures the horror and drama of the battle and surrounding events excellently. I HIGHLY recommend it.

In terms of Roman historians... It really depends on what period you're looking at. Want an awesome insight into the military? Go with Caesar's Commentaries of the Conquest of Gaul. Punic Wars? Check out Livy. Definitely check out Plutarch's Parallel Lives as well.

Of course, the quintessential book on the Roman Empire is Gibbon's Decline and Fall of the Roman Empire. One can hardly consider themselves a Roman scholar without reading it, and nearly every historian will refer to it at some point.

Oh! And there's an interesting one I came across, for a bit more of a lower-look. By a Roman no less! Cookery and Dining in Imperial Rome*, by Apicius is very interesting. Might not be worth it to put on your list, but definitely check it out.

TL;DR: If I have to pick two to add, take the Ghosts of Cannae and Decline and Fall of the Roman Empire. By a Roman, pick from what's relevant.