Preheat oven to 300°F. Lightly butter four 3/4-cup (6 ounce) ramekins and dust the bottoms and sides of each with 1 teaspoon of the breadcrumbs. Set inside a roasting pan large enough to hold the cups without touching.
In a small saucepan, gently heat the cream and thyme. Remove from the heat and let cool slightly.
In a large bowl, beat the eggs and egg yolks. Add the remaining ingredients and whisk together. Add the warm cream and whisk until smooth. Add the Parmesan and whisk to blend. Pour into the prepared custard cups and fill the roasting pan with warm water to come half way up the sides of the ramekins. Bake until set and a knife inserted into the center comes out clean, 35 to 40 minutes.
When the custards are nearly ready, toss the shrimp in a bowl with the Essence to coat. Heat a large, heavy, ungreased skillet over high heat. When very hot, add the shrimp and sear until cooked through, 2 to 3 minutes per side.
Remove from the oven. Remove the cups from the water and wipe dry. Run a thin, sharp knife around the edges to loosen the custards invert onto plates and shake gently to release. Arrange 6 shrimp around each custard and spoon a small amount of the Green Onion Coulis on top and serve.
Makes 4 servings
GREEN ONION COULIS:
Bring a medium pot of salted water to a boil. Add the green onions and blanch for 20 seconds. Remove with a slotted spoon and shock in an ice bath. Remove and dry on towels. Thinly slice and puree in a blender with the olive oil and salt. Adjust the seasoning to taste.