The basic Ayurvedic principle that this lunch practice plays to is that warm, homecooked meals are good for the soul. Come on. Our moms have been telling us this for years. So, in this version, you simply pre-cook some foods very briefly in the morning, and then pour the still-boiling brew into a thermos that it sealed for lunch, 4-hours later.
The basic set-up is the same as what as in this link. You can play with the grains (red lentil and rice is used in the linked recipe), spices (fennel, cumin and coriander are good base spices in Ayurveda), and veggies. A general principle is to “eat what the body needs.” If it is needing some extra fire, maybe add a firy spice. If you are needing to cool it and ground it, perhaps something cooling and grounding.