Weekend cooking: Easy eggs and veggies meal

I found this recipe on the website of Full Plate Living. I believe that the original recipe name was Egg whites and veggies.  In addition to frozen corn, it called for zucchini and mushrooms. However, I am notorious for not sticking to the recipes; therefore, below you will find my version of the meal. The result was delicious despite all my alterations; however, I hope that you will improve upon it, and adjust it to your taste.

Easy eggs and veggies meal
You need: 
3 onions (diced), 1-2 Tbsp olive oil, 10 oz or more sliced mushrooms, 2 large zucchini, diced (I used one large summer squash that was already grilled, and was stored in my freezer), 2 cups of frozen corn, black pepper, winter savory, basil, salt, 1.5 cups shredded sharp Cheddar cheese (or any other cheese you like), 2 boxes of egg whites (16 oz each box).

Directions
Saute onions in oil until caramelized. Add mushrooms, corn, zucchini, spices, and saute for 5-10 minutes. In my first try of this recipe, the mushrooms and zucchini were already cooked, so if you have any leftover veggies, add them to the onions and remove from the heat. The vegetable-spices mixture was then combined with the cheese and egg whites. The mixture was poured into a pan prepared with a no-stick spray (I used 10 x 13 inches pan). Due to the huge volume, it took an hour to bake at 400°F. 

What could I change next time, when I do not have already cooked mushrooms and summer squash? 

I would use a mix of store-bought frozen vegetables and add these to the caramelized onions. I can also add eggs, rather than using only egg whites (or a combination of these). I could change the spices – in this first try, I used black pepper, dry winter savory, fresh basil, and salt. Hot pepper flakes and garlic powder would also make a great addition. 

Have fun, try new combinations based upon the recipe’s main idea!