Which oven are you asking after specifically, riverly?
If it's the Morning Oven - it's used for the first part of the goals so in theory it can be put away once the Morning Mixer is unlocked
If it's the Morning Mixer - this is the appliance that we'll be cooking on until we finish the goal. (The Baked Egg Potato is the first recipe from this appliance, after making and serving 15 of them we still have to unlock and cook the next two recipes from the mixer to complete the goals.)