Okay, found several recipes that have a rustic feel to them, and the major ingredients not included in MineCraft are Bell Peppers, Corn, Onion, and Tomatoes. Supporting crops would be Honeynut Squash, Leeks, Radish, and Turnip. Butter and Cheese also showed up a lot.
Minecraft already includes Carrots, Milk, Potatoes, and Wheat which covers the rest of the core Rustic Farming and Cooking ingredients.
While this solves the question of what crops and cooking ingredients to include, there is still an internal debate over splitting off the parts of the mod that would be strictly decoration options. This would let me focus on the farming and cooking aspects for the main branch of the mod, while making the décor side optional. Looking back at the 1.19.2 Rustic Farming and Décor mod in the MCreator work space, there where actually a lot of items being handled in the mod, so splitting it up could also reduce the risk of file corruption when doing the next major version update.