At least protein itself is a "solved problem".
There's a couple companies making protein from air and nutrients:
https://www.airprotein.com/
https://spacemilk.com/
And Air Protein claims they leveraged NASA's research into the problem so that's a nice payoff.
Algae cultivation would be valuable too:
Complete Protein: Packed with all nine essential amino acids (Spirulina and Chlorella are up to 70% protein by weight).Vegan
Omega-3s: The original marine source of essential EPA and DHA fatty acids, offering a pure alternative to fish oil.
Gut Health & Fiber: Rich in unique prebiotic fibers (like alginate and fucoidan) that feed healthy gut bacteria.
Vitamins & Minerals: High in essential nutrients, including iron, calcium, magnesium, and hard-to-find vitamin B12.
Powerful Antioxidants: Contains protective plant pigments like astaxanthin and beta-carotene for immune and skin health.
Natural Food Additives: Provides functional ingredients like agar and carrageenan used to thicken and stabilize foods naturally.
I'm sure there's other "food from a vat" options that could be baselines, and then augmented by real plant food.
In the interest of efficiency they'd be best served by having a predominantly vegan diet but I imaging that they could have more efficient producers added in, like chicken and fish.