On the trekking trails there is a large range of ( for Westerners ) cheap accommodation and food available. Villages with lodges, teahouses and hotels abound. The trail from Jiri to Lukla is now much less used than previously because so many trekkers fly in to and out of Lukla - this means that this section has the most 'authentic' feel. Trekking is the lifeblood for many of these settlements. Accommodation is usually basic but adequate. There is often a hot shower powered by solar panels ( get in early! ) ... but toilet facilities may be a challenge to some! Menus do not vary hugely ( dal bhaat is the standard dish ) but provide enough choice to ensure you remain well fed.
Kathmandu has a large range of accommodation available to fit all needs and budgets. We can only speak from personal experience but, as an upmarket but good value hotel outside the city centre midway between Kathmandu and Patan, the Summit Hotel will make you feel relatively spoilt! If you really fancy treating yourself at the end of your stay in Kathmandu try Dwarika's for an authentic Nepali meal in quite stunning surroundings.