Chef Morimoto's Momosan (ramen plus other dishes) opened on April 8, 2016, at 342 Lexington Ave (between 38 and 39th St). I've eaten there 4 times, and I really like it.
My favorite is the lunch set. A small don (rice bowl) and small ramen for $16. The zuke don, which is raw tuna with soy, sesame, nori, scallion, over rice, is my absolute favorite. Chunks of very fresh raw tuna with a soy sesame seasoning over rice.
I've had the tonkatsu pork ramen as well as the tan tan - coconut curry ramen - and enjoyed both. The broths are rich. The ramen noodles are good but aren't as springy as the noodles at Daikaya.
I've also enjoyed the chashu salad - lettuce, cucumber, slices of pork.
The dinner menu has a larger selection of appetizers. I didn't care for the duck in crispy wonton skin (like a little taco), but that was because the sauce was sweeter than I like. The buta kimchi -- sauteed pork jowl and kimchi - was flavorful and delicious. The $2 side of rice was on the smaller side, however. I could have gotten 2 sides of rice.