I just slice the succhini and fry it with some onion and green peppers sale and pepper and garlic( you have to cook it to get rid of a lot of the moisture or your frittata will be soggy) then put the cooked veggies in a pie plate add about 2/3 cup crated sharp chedder and whisk eggs, 4 or 5 depending on the amount of the veggies and the size of the pie plate and pour over the veggies, add more beaten egg if the pie plate is not filled,
Then I put it in a 375 oven until it's "set"....doesn't jiggle like liquid when you shake it.
Takes about 45 to 50 minutes....depending on how cold your eggs are and how big your pan.
I have had an "impossible zucchini pie", but don't have a recipe.....
Linda C