Prepare your dough and turn the oven to 350F with the rack in the middle.
Trim the woody ends from the asparagus and cut the remaining stalks on the bias into about 1-inch segments. Slice the zucchini into rounds approximately 1/4-inch thick. Finely chop the spring onions. Prepare other spring vegetables into small pieces as needed.
Heat a large pot of salted water to a boil and place a large bowl of iced water next to it. Blanche your spring vegetables by gently dropping them into the boiling water for one minute until their color brightens and intensifies. Immediately remove the vegetables from the boiling water and place them into the ice water bath. This will stop their cooking while maintaining the beautiful spring colors. After two minutes in the ice bath, remove and place on paper towels to dry off.
Whisk egg yolks, eggs, and half-and-half, a pinch of salt, and some freshly ground pepper together in large bowl. Add the vegetables (including the spring onion) and stir to combine.
Pour half of the egg mixture into the quiche. Sprinkle half the crumbled goat cheese across the egg mixture. Pour in the remaining eggs and sprinkle the last of the goat cheese across the top.
Place the quiche in the oven and cook for 25-30 minutes or until the egg is no longer wobbly when moved. Take out of the oven and let cool for 20-30 minutes. Serve immediately or save and reheat or cool at a later point.