Casein protein shake. Usually have around 40g of casein with water. If you don’t like the taste with water, have it with milk. It will up the calories slightly but that’s fine when you want to gain.
There you go, that’s a good sample of what I eat on a daily basis. That diet right there comes to around 3,350 calories. You can easily adjust the portion sizes to suit your individual calorie needs. If you have any questions post in the comments below https://realweighttraining.com/sample-weight-training-diet-for-muscle-growth