1. Butter a baking dish (9x12).
2. Cut 12 rounds using a circular cookie cutter (about 4 inches in diameter) out of slices of bread.
3. Break up all remaining bread and spread at the bottom of baking dish.
4. Top bread pieces with share cheddar cheese, broccoli, ham and top with bread circles to form a cover.
5. Beat eggs and combine in a bowl with milk, onion, mustard, salt and pepper. Pour over top of the bread circles ensuring to soak all of the bread.
6. Cover and refrigerate overnight or at least for 6 hours.
7. When ready to bake, preheat oven to 325 degrees, uncover and bake for 45 minutes.
8. Remove from oven, sprinkle cheddar cheese over the top and bake for an additional 10 minutes.
9. Remove from oven and rest for 10 minutes.
10. Cut into large squares for you and smaller ones for the kiddos and serve!