Smoothies are my go-to To Go thing. Like the overnight oats I've been eating for breakfast, they use the same base of protein powder, cinnamon, ground ginger, chia, almond milk (unsweetened), and greek yogurt. I grab a multivitamin to fill in the many gaps. Typically, I'll either add organic cocoa power + peanut butter + banana + blueberries or just go with strawberries + blueberries.
Salads are easy prep. Mine get blueberries, too.
The aforementioned overnight oats are fairly quick to make and I make enough for the whole week. I just grab a jar from the fridge and eat it at work. If I can't finish in one aitting, I slap the lid back on and stow it for later. No issues w/ the whey (or casein) protein or fruit (blueberries, strawberries, or mashed banana) lasting until Friday (from a Sunday prep). If using mashed banana, I've been adding nutmeg for a banana bread-like flavor. I always add some crushed walnuts regardless of content. I say crushed because I'm not civilized enough to chop them.