**Spoilers for Project Hail Mary**
I like to think that once Earth receives the beetles and fixes the sun, they then send another beetle to Erid full of seeds, food, spices, and other care package stuff for Grace.
At that point, they won't know he's still alive, as far as they know, he probably starved to death by then. But Stratt insists they send it anyway. If nothing else, it can be a gift for their newly discovered neighbors, the Eridians. Afterall, what's more friendly than sharing food?
The Eridian scientists study the contents of the care package. It's full of shelf-stable human food that they do their best to clone/replicate for Grace. There are also some seeds that store well for the years of travel they experienced. Radish, lettuce, tomato, beans, etc. (Potatoes would be a great callback to "The Martian")
The Eridians are absolutely delighted to observe Grace grow a little garden of Earth plants. Rocky, Adrian, and any of their kids big enough to fit in xenonite EVA suits help him pollinate plants with little paintbrush-like tools. Grace keeps a few plants in pots so he can easily move them around and show them to his students.