Right now, i just bring my post workout shake with me, 2 scoops of whey with 50g of dextrose, down it on the ride home from the gym. Before this, i would eat 1 1/2 to 2 cups of brown rice with 8oz of grilled chicken. there are days when i forget that im low on rice and didnt cook it, i will always have white rice in the fridge(myfamily eats white rice everyday), so i will use the white rice, doesnt matter much since its post workout. if i dont have any chicken or fish defrosted which is rare (if you fail to prepare, you prepare to fail), i will eat 3 slices of white bread with 1 tbs, of jelly or honey on each slice, then 2 scoops of whey with water.
other options include, 1 large or 2 medium bananas, and 2 scoops of whey. 1 cup oatmeal (uncooked) blended with 2 scoops of whey and water. just be creative, i just gave you 5 examples, they all add up to about 500-550 calories. just make sure you eat carbs (slow or fast digesting) and protein, keep fat intake minimal or none.