Fill a large bowl with ice water to create an ice bath.
Bring a large pot of lightly salted water to a boil. Add broccoli and cook, uncovered, until bright green and tender, about 3 minutes. Drain in a colander and immediately immerse in the ice bath for several minutes to stop the cooking process. Drain.
Preheat oven to 180 degrees C. Lightly grease a 22cm x 32cm casserole dish with vegetable oil.
Combine broccoli, cottage cheese, eggs, Cheddar cheese, butter, flour, salt and pepper in a large bowl. Spread into the prepared casserole dish.
Bake in the preheated oven, uncovered, until a knife inserted into the center comes out clean, about 60 minutes.
If using a glass casserole dish adjust oven temperature to 165 degrees C.