USDA Summer Food Service Program's Lunch Meal Pattern.
My chart is pretty easy to emulate, columns for days of the week, and 4 different-colored rows* for: Vegetables, Fruits, Proteins, and Grains. I then printed little colored cards whose backgrounds corresponded with the columns, labeled with all the different items we rotate through for lunch: I surprised myself by finding our standard repertoire had over 60 items for him to choose from; 15 in each category! For instance, there are options you are all familiar with: PB&J on sliced bread with a side of grape tomatoes and an orange. Sometimes, we have more international lunches: Tamago (omelet) sushi with a thermos of miso soup and Inarizushi (rice-stuffed tofu) and kiwi. There are a couple of vegetarian and even vegan options (so beans could be in both the vegetable and protein categories.) I also offered pasta options, separating the sauces and toppings on the chart to fit them in the appropriate category - so mac and cheese, and spaghetti with Italian sausage and marinara.
(*technically, there are 5 components to lunches in the USDA meal planner, but I omitted dairy from my chart under the assumption that most kids, even those who pack, purchase milk at school - and Sparky gets lactose-reduced milk at home with his afterschool snack.)
(this week's menu: Mon - a banana-nutella wrap with bell pepper on the side; Tue - Tamago, Inarizushi, Miso soup and Strawberries; Wed - 7-layer dip with chips, assorted veggies, and watermelon; Thur - Assorted cheese and crackers with grape tomatoes and kiwi; Fri - Tofu and Egg salad on sliced bread with snow peas, and clementines.)