Suggestions

Cereal (weetbix, cornflakes, whatever you eat) - variety packs are good because you can eat them out of the little box

Hot cereal and raisins

Milk - powdered or longlife

Apple or other hard fruit

Nutbar or energy bar

Hardboiled egg

Bread / sandwich

One square meal

Other possibilities

Hot drink - coffee or tea

Up and Go - doesn't have much substance, it's only fluid