Like most action RPG games, Genshin Impact allows you to restore your health by eating food. In the original release, you had to open your inventory and manually select the food item to eat it.
In version 1.1, the game introduced gadgets, including the NRE (Menu 30).
This gadget has two slots to hold one HP-recovery food and one revival food.
Where to Get the NRE (Menu 30) Gadget
You can craft this gadget with the help of a blacksmith. The blueprint is a reward when you reach City Reputation level 5 in Mondstadt.
Open your inventory and click on the item once you are done forging the NRE gadget. This will allow you to select what HP-recovery and revival food to use. Click “Equip,” and the gadget is now available on your screen.
After equipping the gadget and selecting the recovery items, you can use a hotkey to consume them.