Preheat the oven to 400 degrees F.
Place the Jerusalem artichokes and potatoes in a mixing bowl and season with the salt, black pepper, and cayenne. Mix in 2 tablespoons of the olive oil and toss to coat.
Butter the bottom and sides of a 2 quart baking dish. Put half of the artichoke-potato mixture in the bottom of the pan, then sprinkle with 1/4 cup of the chopped onions, 1 teaspoon of the chopped garlic, and 1/4 cup of the cheese and the flour. Top this with the remaining artichoke-potato mixture. Sprinkle with the remaining 1/4 cup onions, 1 teaspoon garlic, and 1/2 cup cheese. Pour the milk over the mixture.
In a bowl, mix together the remaining 2 tablespoons olive oil with the bread crumbs, parsley and season with Essence. Spread this topping evenly over the mixture. Bake for 1 hour, or until the potatoes are tender.
Combine all ingredients thoroughly and store in an airtight jar or container.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch. Published by William and Morrow, 1993.
Recipe from Louisiana Real and Rustic Cookbook by Emeril Lagasse; William Morrow Publishing