The Packed Portions Cooking Week Part 2 event will run in Pokémon Sleep from December 1 to 8, bringing new bonuses and a fresh addition to the game. Spiritomb will debut to coincide with the event, giving players a new Pokémon to research as they cook and sleep their way through the week. With special dishes and boosted rewards expected, this event is a great chance to progress and add Spiritomb to your roster. Be sure to log in daily so you don’t miss any of the limited-time perks.
Source: Official Pokémon Sleep news and PokemonSleep.net