Zachary went to school yesterday with a muesli bento (and some grapes, grape tomatoes and baby carrots). Milk to add later was in a separate container.
Here's our recipe for muesli, which we don't usually have for lunch, but Zachary had a little trouble getting up, so he got his breakfast for lunch:
3 cups rolled oats
1 cup nuts (we used slivered almonds, and chopped walnuts and cashews)
1/2 cup sesame seeds
1/2 cup sunflower seeds
1/2 cup pepitas
handful of chia seeds
1/2 cup cranberries
1/2 cup raisins
1 cup chopped apricots
Into each serving we usually add honey or maple syrup and fresh fruit.