In a food processor, blend together either raw or thawed from frozen broccoli and cauliflower florets. Pulse and scrape the food processor down with a wooden spoon until you have a consistent mixture of fine, crumbly pieces.
At this point, preheat an oven to 350 degrees. In 4-5 additions, squeeze the liquid out of the broccoli/cauliflower mixture and transfer the mixture to a large mixing bowl. You can squeeze out the liquid using a paper towel or a thin kitchen cloth (the cloth will work better). The less excess liquid, the better your garlic bread will turn out.
In the large mixing bowl, stir the parmesan, egg, salt, pepper, garlic, and oregano into the mixture. Then, press the mixture into a 9×13 sheet pan lined with parchment paper, filling all the corners and edges.
Bake the tray for 15 minutes. Then, sprinkle the cheddar cheese over the top of the garlic bread base. Bake for final 10 minutes – until the edges of the garlic bread are golden brown and the cheese is melted.
Allow the garlic bread to cool for 5 minutes. Then, slide the parchment paper out from the tray, and slice the garlic bread into 12 rectangular slices. Enjoy!