heres a recipe to get FAT:
BREAKFAST!!! (eat 2 hrs after waking in which time eat nothing)
2-3 toasts with fish fingers, beans, whatever (you can have jam but youll be missing out on calories) = approx 250 calories (or your normal hot breakfast)
now 400ml of whole milk + 2 raw eggs + banana + 2-3 table spoons of white sugar + BLENDER = (according to my calculations) 656 calories
for a grand total of approx 1000 calories. MashAllah thats 40% of a normal persons eating done with the first meal. bear in mind eating until you feel sick is makruh, so you can break this down over 2 meals inshallah.
make sure you eat the toast first because the milkshake tends to go down no problem. but if you drink the shake 1st you may have trouble eating the proper meal.
now here are good foods for calories and protein : fried chicken, nuts like almonds and peanuts, potatoes (even chips but make sure they are almost 100% potato), rice, roti + boti (or paratha + boti) lol, baked beans, pizza.