75 to 90 kg goal

Just to gain weight? Food high enough in calories to gain weight. If you're looking to gain muscle then please give a bit more information: what do you want to do, do you have equipment or a gym, etc.

Food with calories above your weight maintenance calories that adds up to reasonable overall nutrition, especially but not exclusively ample protein. For protein, maybe at least 144g protein daily, and more could be a good thing, up to maybe 200g if you can get that while also getting other nutrition you need (healthy fats, micronutrients, fiber).

If you want to gain more muscle than fat, lift weights or do other progressive strength exercise while gaining, and don't gain much faster than a quarter to maybe half kilo per week, or more than minimal amount of the gain will be fat.

If you struggle to gain, this could be a useful thread:

http://community.myfitnesspal.com/en/discussion/10326769/are-you-a-hard-gainer-please-read#latest