if you wanna be healthy about it, eat as you do and eat what you like, and just make yourself a "hardgainer shake" after workouts.

normal dose of protein powder in milk/soymilk/almondmilk
a hefty slab of peanut butter
tbsp olive oil
1/4 cup egg white, or a whole egg. I use the pasteurized liquid egg product so I don't have to worry about salmonella
maybe half a banana

800 calories