Make three lunches. Couscous contains wheat; yogurt contains milk. For alternatives, use cooked quinoa and a suitable dressing, following their preparation instructions.
Keep at 4°C or below and plan to eat these three lunches over the next three days. Refrigerate perishables within two hours, or one hour above 32°C. Transport with adequate chilling. Discard food left outside safe temperature control too long; smell is not a reliable safety test.
Before shopping again, note whether the grain, vegetables, or dressing was left over. Adjust one quantity for the next batch while keeping the stated storage plan.