Only made it for the late night menu on our first visit, so the only German cuisine available was a sausage platter, which was good enough. There was a BOGO on the Green Mill pizzas so we ended up going that route for the main course. I will definitely recommend the Apple Strudel. While some may consider it a little pricey at $6, I would say it was worth every penny! Truly delicious.
The service was excellent, and the staff was very friendly and accommodating in every way possible!!
My wife and I only attended their Sunday brunch buffet so can't comment about their regular lunch or dinner menus. The service and staff were also all decent. While the hostesses were pretty much brain dead, the servers were all pleasant and attentive. My rating is only the food.
We were expecting something a little German from a restaurant that certainly wishes to give off the German restaurant impression. The only German food available was sauerkraut. The buffet consisted of two rooms. One containing more traditional breakfast items like sausage and eggs. That part was fine and what you'd expect from any breakfast buffet. The other room was something else.
The second room was a selection of random, unlabeled steamer trays. It was the Island of Misfit dishes. There was some super salty pork thing, chimichungas and spanish style rice, and probably one of the worst things I've ever tried, meatballs in what I am pretty certain was French dressing. There was some random Mexican pasta dish and your mystery brown gravy with mashed potatoes. There were a few other steamer tray options I don't recall and a carving station that had ham and maybe beef. I didn't feel tempted to risk those. We returned to the table with our meager selection (bacon and eggs) with matching disappointed looks on our faces.
For $15 each, I would have hoped for something a little more memorable and not so yuck.
I spent a month at the Holiday Inn so I got to work through the menu a few times. Nate, Marti, Hugh and the entire staff do a great job of making great food, and getting it to you. The German dishes are  very good, fairly authentic. Make sure you try the prime rib (Fri & Sat nights, and maybe on Sunday Brunch). Speaking of Sunday Brunch, don't miss it. Everything from basic eggs, saugage, etc, to make your own waffle, to omlette bar, to lunch items, to carving station.
The full menu is available fairly late, and there is a late night menu, too.
While in New Ulm drink the Schell's products. 1919 is a root beer like no  other. The Grain Belt and Hauenstein are for lighter tastes and the Nordeast and Firebrick and fuller bodied. Yes Taylor, Snowstorm is seasonal, as is the Maiboch.
The popovers are awesome early, and tend to get hard as the evening goes on. Coupons are available online.
Can't forget the Green Mill pizza. Very I preferred the hand tossed crust. The ingredients are fresh and tasty. Try the Romano - very tasty.
Green Mill pizza at Otto's rocks! New Ulm is my one standing exception to "no pizza on business travel" rule. Also, last week Ashley (at least I think that's her name) went out of her way and came in early 3 days to make breakfast pizzas, which I took into work. The locals said they were better than Happy Joe's! We hope Green Mill adds them to the menu :) Â They did a great job going above & beyond!!
Review Source:Nestled in a small German town, sits a house of lodging that  goes by the name Holiday Inn, nested within this house was a small German restaurant.  Their bread and butter so to speak is schnitzel and gravy and that they do well.  A rabbit to mix things up is a nice touch for the adventureous (thought it could have spent more time on the fire to warm my belly).  The rest of the food is fairly week, the famous popovers did not bowl many of us over.  You're in New Ulm, however, were the beer is good; drink the local Schell draught.  My favorite is Snowstorm (I'll take a jump and guess that it's seasonal).  Firebrick was also a group favorite.  Around the bar a few locals, Churchill look-a-like amongst them, discuss politics late in the late with traveling businessmen and a few young people.  The waitress Stefanie and bartender Linda were cheerful, talkative and did pretty well taking care of us.  It was like my corner bar and restaurant for the 3 weeks I was there. Â
PS It was negative twenty degrees and there was no way in hell I was leaving without a NASA spacesuit.