Like almost every other Thai restaurant in the Twin Cities (and maybe the US, from what I've seen), King and I offers a menu full of seemingly-vegan/vegetarian dishes which are not, in fact, vegan or vegetarian. Indeed, fish sauce or shrimp paste is lurking in every corner. Ask questions, people!
Indeed, the red and green curries at King and I contain shrimp paste and cannot be made vegan. Also, the "Roasted Red Pepper Sauce" dish cannot be made vegan.
However, there were a couple of other dishes that we could work with. We shared a "Holy Basil Sauce" with fried tofu ($17.50) which was spicy and loaded with tofu and basil. The portion size is huge (it's easily enough for 3 or 4 meals), which sort of justifies the unusually high price tag, though I would prefer a smaller dish at a smaller price. For $17.50 you expect a 4-star dinner or maybe a 5-star lunch; King and I is but a generic Thai restaurant at the end of the day. This first dish was good, maybe even above-average, but it wasn't gourmet or spectacular.
We also shared a "Palatial" modified to be vegan with tofu ($17.50). Since the red and green coconut curries contain shrimp paste, The Palatial is the closest thing at King and I you'll get to a proper curry---it's basically a stir-fry with vegetables and tofu or mock duck, covered in thick, creamy coconut milk. The dish was slightly bland as it was served, but we added some garlic chili sauce and suddenly it became quite good. Again, the portion size is huge, and the food is good, but it's not outstanding.
King and I does have great atmosphere. The main dining room is a bit staid, but properly formal, whereas the bar area where we sat was lively, yet comfortable and calm enough for a romantic dinner. The bar is cozy and chill and feels like a neighborhood joint; I'll definitely be coming back for a drink at some point.
The service was excellent. Our server, a young woman with glasses, was extremely friendly and attentive and kept checking with the kitchen to see what could be made vegan. Moreover, she told immediately that the curries were not vegan or vegetarian and could not be modified, which suggested to me that she's conscientious and thorough about ingredient issues. She also went out of her way to prepare an all-vegan spice rack for us, with three types of chili sauces, sans fish sauce.
All in all, King and I is a good place, though very expensive (but at least the portion sizes are enormous). They don't offer brown rice, which is a bummer, and they also will charge you $1 for extra white rice, which is a double bummer. That said, this is a good place to get a drink and maybe split a dish with two other people.