Preheat the oven to 350 ℉ and butter 4 eight-ounce ramekins and set aside.
Cut the asparagus and steam until fork tender, about 3-4 minutes, depending on the thickness of the asparagus. Remove the asparagus from the steamer and quickly transfer it to an ice bath to stop the cooking process.
In a food processor or blender, puree the asparagus until creamy.
In a medium size bowl, whisk together the eggs, egg yolks, cream, salt, pepper, and pinch of nutmeg until combined. Add asparagus puree and the parmesan cheese and whisk to combine.
Fill the ramekin halfway up (between 4 to 6 ramekins) and set them in a baking dish. Add enough hot water to reach halfway up the sides of the ramekins.
Bake for 25-30 minutes. The timbale is done when it's firm to a light touch or when a small knife inserted in the middle comes out clean. Remove the ramekins from the waterbath, set them on a metal cooling rack, and let them cool before unmolding and serving.
Notes
Asparagus: Choose fresh, bright green asparagus with tight tips. For 1 cup puree, you will need about 1 large bundle of asparagus. Bundles vary from market to market, so look for one that weighs about 1 lb. Depending on the size, you may have slightly more puree than you need. If it's close to 2 cups of puree, double the recipe. If it's slightly more than 1 cup, I add it to the recipe as written.