Nepal is a place where worlds collide. In altitude alone, Nepal is home to the world's tallest mountain (8 of the 10 tallest in fact) and places that are almost sea level. The East meets the West, as does the North the South as Nepalis have their own time zone based off Mount Everest. They are the only country in the world with a non-rectangular flag. Their flag is two stacked triangles meant to represent Hinduism and Buddhism. While the cultures of the surrounding countries go back thousands of years, most of their political identities are formed out of colonialism. Thus, these other countries are relatively new. Nepal has never been colonized, and this makes it one of the oldest countries in the region.
Due to its unique location, Nepali food is one of those foods that is at the crossroads of of the East and the West. Momos, are one example of how Nepal's location infuse its food with diverse flavors. Kathmandu and Kabul (The capitals of Nepal and Afghanistan respectively) are exactly 1,000 miles apart and yet there is a distinct similarity between Nepali Momos and Afghani Mantoo. Momo is a dumpling that is usually filled with minced buffalo, chicken, or pork. We tried the chicken ones. It is clear that momos have strong roots in China, and yet they are distinctly different from your typical dim sum style Chinese dumplings. Momos are served as their own dish, or can be added to dishes like soup and they are served everywhere in Nepal.
With its close association with India to the south, eaters will also recognize some familiar flavors and dish styles. Common dishes are things like curries, tikas, and Pulao (Rice ands meat, like biryani). One of the unique flavors of Nepali cuisine is the use of Achar. Achar is usually translated as pickle (or spicy pickle), is not made from or with pickles, which leaves even experienced eaters wondering "where are the pickles?" Achar, is a savory fruit and vegetable (often a tomato sauce) based sauce used for stewing and simmering meat and fish.
Nepali food should be on your short list of foods to try, but it should be eaten in conjunction with a eating tour that includes Afghani, Western Chinese, and Indian cuisine.