How to Make It
Place the green beans, onion, and 1/4 cup water in a medium skillet. Bring to a boil over medium-high. Cook until the water has evaporated, about 5 minutes. Add 1 1/2 teaspoons of the oil, and 1/8 teaspoon each of the salt and pepper; cook until the beans and onions are tender, about 5 minutes longer. Transfer to a plate. Reserve half for Day 2 Lunch.
Add the remaining 1 1/2 teaspoons oil to the skillet, and swirl to coat. Add the tomatoes and corn; cook, stirring occasionally, until the tomatoes burst and the corn is charred. Toss with the lemon juice and remaining 1/8 teaspoon each salt and pepper. Reserve half for Day 3 Dinner. Add the remaining corn and tomatoes to the plate with the green beans.