Wash the kabocha squash thoroughly, peel it, and cut it into bite-sized pieces.
Place the kabocha squash in a steamer and steam for 15 minutes until cooked through.
Cut the broccoli and carrots into bite-sized pieces and blanch them in boiling water.
Put rice into the lunch box container.
Arrange the cooked kabocha, broccoli, carrots, and other vegetables neatly in the lunch box.
Add a protein source like chicken breast or eggs together.