Combine 6 eggs, 3 egg yolks in a large bowl and whisk until blended. Mix in 1 tablespoon mustard, 1/2 teaspoon salt and 1/4 teaspoon white pepper. Add 3 shakes Tabasco, 1/4 teaspoon fresh nutmeg, grated. Add 1 1/2 cups heavy cream, whisk gently until incorporated.

FILLING:

Melt 2 tablespoons butter in saucepan. When it begins to bubble add 1/4 cup sliced mushrooms, 2 cloves garlic, minced. As soon as mushrooms begin to give up their juices, pour 1/8 to 1/4 cup sherry around edge of pan, continue to simmer for one minute. Remove from heat and add 1/4 cup chopped green onions.

Cool. Once cooled, add 4 ounces shrimp, cleaned and cooked. Divide 1 avocado in half and cut each half lengthwise into 4 equal slices. Skin slices.

Put on frozen quiche crust, 1 1/2 cups (4 to 5 ounces) gruyere, grated coarsely; sprinkle 1/2 cup grated Parmesan on top. Spoon filling evenly over cheese. Gently arrange avocado slices in an even wagon wheel pattern around quiche. Set quiche on baking sheet; bake for 1 to 1 1/4 hours until light brown and beginning to puff up. Small cracks will begin to appear around the edges. It will fall slightly when you take it out and cool. Let it rest for at least 15 minutes before cutting to serve.