Bake the tart shell. Let it cool completely.
prepare the cream
Preheat the oven to 175 degrees C / 350 degrees F. Prepare the cream. In a bowl mix together the mascarpone, ricotta, sour cream, eggs, thyme, oregano, lemon juice and nutmeg. The mixture will be smooth and runny. Season to taster with salt and pepper.
clean the asparagus
Clean the asparagus and then bend each stalk and snap off the woody end. Cut them to 10 cm (4 inch) stalks and set aside. Chop the rest of the asparagus onto small chunks and stir them into the creamy mixture.
bake the tart
Pour the creamy mixture into the prebaked tart shell. Place in the oven and bake for 30 minutes at 175 degrees C / 350 degrees F. Meanwhile pan fry the asparagus.
Take the tart out of the oven. Arrange the pan fried asparagus over the creamy mixture and return to the oven. Bake for additional 10 - 15 minutes. The filling must still be wobbly in the center. Remove from the oven, let it cool, then serve. Enjoy.