Tutorial Fiefs
Probably the aspect of settlements that is most changed by the mod. You'll likely have noticed that food is produced and consumed by the hundreds instead of dozens like in vanilla. That is because every single pop in a town will be consuming food, like all human beings do. Different classes consume different amounts, but the baseline food consumption ratio in the game is 1 food = 20 people for 1 day.
Most of the relevant things around food are present in Demesne Management, Demesne tab.
This is the single most important aspect of food. Food is produced on land and medieval land is divided in lots called acres. Every settlement is assigned an acreage once the mod spins up the first time. In towns, this is used to determine how much food can be produced. Most of the food comes from the farmland type acreage, a little from pastureland, and marginal amounts from woodland.
Therefore, in other to be able to produce more food, you need more acreage. But land doesn't farm itself.
Serfs and slaves serve as workforce in fiefs. Mostly, this means farming hands. In towns, all serfs can contribute as workforce, while only slaves only do when they're state slaves. The more workforce you have, the more acres can be worked on.
It is important to note the Workforce Saturation meter. Each acre requires an X amount of workers. Having less workers than what is needed, means that not all acres are being fully worked (saturation < 100%), thus food potential is not being fulfilled. On the other hand, having more workers than needed (saturation > 100%) means you have spare workers that are unable to work any land (and thus are consuming, but not producing food).
Therefore, ideally you want to aim for 100% workforce saturation, to maximize the food production potential and minimize the consumption of your workforce classes.
Keep in mind: construction projects and workforce policies will use workforce! Therefore, if you may want to stop all projects that aren't considered "daily projects" and set your Workforce Policy to None.
A more immediate of feeding your settlements is using the stash. The mod makes it so that all food items in the stash are converted into town food stocks, 1 to 1. Simply drop foodstuffs into the stash and they'll be used when food stocks are severely depleted.
Some policies provided by the mod are relevant to food consumption and production. I mentioned above acreage. You might have asked yourself, what if the town needs more acres? For this we have the Land Expansion policy, under the Workforce Policy category, which is mentioned up in the Workforce description.
This is not a feature used by the player, but the mod also makes the population wipe out market supply of food. In the base game, the fief keeps on starving with a market full of food. Now, if they need 500 food items, they will buy 500 food items from the market, if they are available. This is only triggered when the town's food stocks are severely depleted.