Preheat the oven to 425 degrees F. In a large bowl, whisk the eggs, garlic, milk, yeast, and half the salt.
Heat the oil in a large skillet over medium, then saute the onion until translucent, about 5 minutes.
Add the broccoli and water, then cover and steam 3 minutes. Uncover and stir in the spinach, green onions, and remaining salt until the spinach has wilted, about another minute.
Transfer to a baking dish and pour the egg mixture on top, then bake until just about set, 15 to 20 minutes.