Preheat your oven to 350 degrees Fahrenheit and grease a 9-inch pie dish.
In a large bowl, combine the Bisquick mix, shredded zucchini, diced onion cheddar cheese (don't forget to reserve some for the end!), parsley, salt and pepper, oregano, and garlic powder, mixing well.
Measure the oil into a liquid measuring cup and add the eggs, breaking them up with a fork and beating them lightly.
Pour the oil and egg mixture into the bowl with the other ingredients and mix well until fully combined.
Spoon the mixture into the prepared pie dish and smooth out the top.
Add the remaining cheddar cheese over the top, and bake at 350 degrees Fahrenheit for 30-35 minutes or until the top is golden brown and springs back to the touch.
Let cool for 10 minutes or so before slicing and enjoying.