Turn the oven to 360 or so. Get out 2 8×8 pans, a bowl for nuking broccoli, and a blender.

Nuke broccoli, perhaps 12 minutes. It needs to be thawed but it doesn't need to be fully cooked.

Blend everything. You should have about 72oz of yellow glop with suspended green particles. Pour half into each pan.

Bake for around 40, 45 minutes until there's some color on top and a knife comes out clean. Let it cool a bit, or refrigerate.