1. Preheat the oven to 350 degrees.
2. Using a serrated knife, cut the bread lengthwise into 1" strips without cutting through the bottom.
3. Cut the bread widthwise into 1" strips, again without cutting through the bottom.
4. Insert the cheese into the slits.
5. Mix the butter, onions and poppy seeds.
6. Take a cookie sheet and line that with aluminum foil.
7. Place the bread on the cookie sheet.
8. Pour butter and onion mixture over the bread.
9. Seal the bread in the foil.
10. Bake in oven for 20 minutes at 350 degrees.
11. Put the onion cheese bread on a serving platter and serve hot.