This request can be picked up from Choy, the Vendor in Jubilife Village. It’ll be available to you once you’ve quelled the first Frenzied Noble and have access to Crimson Mirelands. Choy asks you to give x3 Hearty Grains to Tao Hua, who’s found in the basement of Galaxy Hall.
Where to Find Hearty Grains in ARCEUS
Hearty Grains can be found in the Golden Lowlands, found south of the first camp in Crimson Mirelands. Look out for patches of tall, golden wheat and you’ll find some small bunches of Heart Grains nearby.
Once you have three, head to the basement of Galaxy Hall and hand over the hearty grains to Tao Hua. Afterwards, report back to Choy to finish the request. You’ll now have more items available to purchase at his store!