We visited Morgenstedet on our holiday, and they opened about 12:30 (instead of 12, which is their stated opening time). It was cozy with a really good serving size in relation to the prize. However, I wish I'd known that the tortilla i chose was very spicy! I hardly managed to eat it (me and my stomach are not great fans of spices)... But it was one of the things they at least thought were onion free (you'd be surprised how seldom restaurants can tell you what their food contains, except for more common allergens like dairy) and I'd paid for it... My boyfriend loved his mushroom stew, though. It was really great to find an all-vegetarian organic restaurant, and I recommend it! (Especially if you're not allergic to anything and can choose freely from their menu.)
A sidenote: If you're afraid of dogs, I would warn you against entering Christiania in the first place (we noticed that there were lose dogs everywhere outdoors).
Cons: Unclear what ingredients food contained, Opened later than stated, A bit difficult to find (no real maps)