While Nepal is a Hindu kingdom & therefore regard the cow highly, there are places to get steak. The 2 major ones are Kilroy's of Kathmandu & K-Too, which is an off-shoot of Kilroys. Both places have an excellent atmosphere about them for the westerner who needs a taste of home. The Menu has a good variety of steak & chicken dishes.
K-too is located just down the street from Casa della Pasta & "Barnes & Noble" bookstore, before you reach the Roadhouse Cafe. It's an upstairs resturant with a very rugged look. One of the dishes I must recomend, when in season, is the apple mo-mo's... They are a must with ice cream.
Kilroy's is a bit harder to get too but most know where it is so ask around. It has an excellent outside dinning area with a waterfall & big group table shaped like a tree stump. They have excellent sandwhiches & chips/french fries.