Well, if you want to put on weight, you have to eat more calories than what your daily "maintenance calories" are. Something in the order of an extra 500 calories per day will give you approximately a one pound weight increase over one week. In order to encourage muscle growth, you have to work those muscles and not just sit around and put on fat. I know it's certainly not easy to do if you're feeling tired, but remember that energizing feeling you get after a good workout. Find something physical to do, that you enjoy and agrees with you. If you can lift some weights, great. If you don't have access to anything like that (or just are not that way inclined), doing some bodyweight exercises at home will be helpful. Adding a few basic pieces of equipment can add some variety and they don't have to take a lot of space depending on what you choose. I have a pullup bar that I mount on a door, an inflatible stability ball, and a set of dumbbells. Just remember that you have to pick something that is going to build muscle - high cardio things like running don't cut it here, and will just burn off your calories without adding much muscle mass. If you're not already working out very much, it is important to start out slow! Do some pushups, situps and some pilates-type exercises and increase the amount daily.

I hear you on being sick of the high fat/high dairy diet. It was the same for me. Definitely you'll want to add whey protein powder to your diet. There are quite a few different types with various additives out there, but you'll probably want to pick a more basic plain whey protein. I always have vanilla on hand, and rotate between other flavours for a second option.

There are lots of non-meat sources that are high in protein. Quinoa, lentils, chickpeas (garbanzo beans), edamame (soybeans), greek yogurt, etc. Nuts have a lot of protein but they are also very high in fat. If you can tolerate chicken or turkey breast meat, it is also higher in protein and relatively low in fat.

Recipes will vary on what foods you can tolerate and what is available to you. I like to make a big pot of chili overnight in my crock pot, using a variety of beans and chickpeas. Add in some Indian dishes like daal to get your lentils, and chana masala for some more chickpeas. I also buy the edamame that you just pop in the microwave for a few minutes and steam in a bag (or the already shelled ones that I can add to a stirfry).

I'm not sure how you will tolerate any of that while on chemo, however. Soups, smoothies and fresh vegetable juice might be all you can handle. If you don't have a blender, I'd highly recommend that you get one. It'll become your best friend.