Cut your beef sausage into 10x 1/2" pieces (~1cm)
Chop the onions into thin slices and sauté them in some olive oil for 5 mins on low.
Chop the sorrel (spinach or what have you), add it to the pan and cook for another 5 minutes until both greens change texture
Preheat the oven to 350 F (180 C)
Grab a bowl, crack 3 eggs and mix thoroughly
Add the ricotta, cottage cheese, salt & pepper. Mix again
Wet a deep oven-safe tray with some olive oil
Pour the mixture from the bowl into the tray
Distribute the sausage slices evenly on top and put in the oven for 20 minutes
Take the tray out of the oven, grate the cheddar cheese all over the top and put it back for another 10 minutes
After the time is up, take out the casserole and leave for a while to cool before slicing & serving. This will allow the cheddar to solidify so you can get some nice identical pieces
Garnish with fresh parsley & cherry tomatoes