Preheat oven to 350 degrees and spray a mini muffin tin with olive oil.
Whisk the eggs, milk, and water together in a big bowl.
Place the asparagus, green onions, zucchini, and dill into a separate bowl and mix well to incorporate. Place veggie mixture evenly into muffin tin.
Pour the egg mixture into each mini muffin cup leaving some room at the top for it to expand while cooking.
Place into the oven on the center rack and bake for 25 minutes until eggs are completely cooked through.
Remove from oven and let cool for 2 minutes. Lift each omelette out of the muffin tin using a dull knife and serve.