Moretum was a common Roman recipe and it’s easy to make at home.
Making the cheese
You can start by buying ricotta, but you can also make your own ricotta. Pour about half a gallon of milk into a saucepan. Heat until it’s almost boiling, and while you’re waiting mix 1/4 cup of vinegar with 1/4 cup of warm water. When the milk is hot, add the vinegar and stir gently for a couple of minutes. Then turn off the heat and leave your cheese for ten minutes. It should separate into curds and whey. Drain the whey off in a colander lined with cheesecloth or an old t-shirt. Leave it about half an hour. (or just buy ricotta)
Chopping herbs and garlic
While the cheese is draining, chop up 2 cloves of garlic, a couple of small green onions, a stalk of celery, a cup of flat Italian parsley, and a cup of cilantro, (or use some mint if you like). Chop them fine, and then if you have a mortar and pestle grind them up in that. Put the chopped things in a bowl, and add the cheese. Mix that all together with a little oil and vinegar, and a large pinch of salt. Spread it on plain crackers.
The Classical Cookbook, by Andrew Dalby (1996). Both rich and poor people’s recipes, with a lot of context too.
A Taste of Ancient Rome, by Ilaria Gozzini Giacosa (reprinted 1994). Recipes from Apicius, including the weird ones.
Ancient Roman Feasts and Recipes Adapted for Modern Cooking, by Jon Solomon (1977). A history of Roman food, and then about a hundred Roman recipes you can make.
Around the Table of the Romans: Food and Feasting in Ancient Rome, by Patrick Faas (2002).