My solution

However in the instructions it is said to write the instructions in a single line, I succeeded only in using two, this is my code, i hope it helps you!!

available_items = {"health potion": 10, "cake of the cure": 5, "green elixir": 20, "strength sandwich": 25, "stamina grains": 15, "power stew": 30}
health_points = 20
health_points+=available_items.get("stamina grains",0)
available_items.pop("stamina grains",0)
health_points+=available_items.get("power stew",0)
available_items.pop("power stew",0)
health_points+=available_items.get("mystic bread",0)
available_items.pop("mystic bread",0)
print(available_items)
print(health_points)