PLACE egg in a medium saucepan and fill with water, covering the egg 1-2 inches. Bring water to a full, rolling boil and cover the saucepan. Remove from heat and let it stand for 12 minutes, covered.
DRAIN hot water and transfer egg to a bowl filled with cold water.
PEEL the egg and transfer to a fun egg mold. Close mold and let it sit for 5 minutes. Carefully remove from mold and set in bento box.
COMBINE mayonnaise, ketchup and lime juice in a small bowl. Stir to combine.
SPREAD mayonnaise/ketchup on sandwich slices. Add cheese and ham slice. Using a large star shape cutter, cut sandwich and place in bento box.
FILL in open bento box spaces with tortilla chips, salad greens or sprouts, strawberries and small star cheese cut outs. Finish by piercing strawberries with decorative picks for a fun effect.