In a hot saute pan, add 1 tablespoon of oil and saute garlic. Add mushrooms and mix carefully. Season with salt and pepper. Deglaze with wine and reduce until nearly dry. Check for seasoning and lay mushrooms on a tray to cool completely. In a large bowl, whisk together eggs and cream. Mix in cooled mushrooms and scallions. Spray 4 large ramekins with cooking spray and fill 4/5. Place in hot bain marie (boiling water up half way) and bake in oven at 300 degrees for 25 minutes or until set.
In a 1 quart casserole, add 1 tablespoon butter and sweat onions and garlic until soft. Add water and season well. Add the asparagus and cook for only 3 to 5 minutes until soft. Add the spinach and take the casserole off of the heat. (It is imperative that this water tastes salty so that when the asparagus and spinach are added, they maintain their green color.) Immediately buzz the sauce with a hand blender and add the butter. Check for seasoning. Add the truffle oil and keep warm in a water bath.
In a large pasta bowl, ladle in the asparagus sauce. Place one custard in the middle and garnish with asparagus spears, truffle oil and fresh truffle slices.