Heat oven to 375°.
Roll out pastry and using the bottom of the tart shell as a guide, cut the pastry dough approximately 2-3 inches away from the bottom tart shell, as this gives you the extra you need for the sides of the tart or measure a 12 inch circle. Place the dough in the shell and lightly press the sides. Using a rolling pin, roll over the tart pan, and this will cut the extra pastry.
Fill the tart with dried beans or pie weights and bake for 20-25 minutes, until the crust becomes lightly golden and baked. Remove from the oven, set on wire rack to cool and remove the beans.
In a skillet over low-medium heat, add olive oil, and sauté the asparagus, and zucchini, about 3-4 minutes and once softened, set aside.
Beat eggs, stir in flour, milk, cream, cheddar cheese, thyme, salt and pepper.
Place the tart on a baking sheet, then add the scallions, then pour in the egg mixture, and arrange the zucchini and kale.
Bake for 35 minutes, or until knife inserted in the center comes out clean.
Let cool for 5 minutes and serve.