Preheat the oven to 400 degrees F.
Cut the upper half from each tomato and scoop out the seeds and pulp. Sprinkle insides of the tomatoes lightly with salt, and invert on paper towels to drain for 20 minutes.
In a small, heavy saucepan, melt the butter over medium heat. Add the shallots and cook, stirring, for 2 minutes. Stir in the flour, and cook, stirring, for 3 minutes. Whisk in the cream, and simmer, stirring constantly, for 5 minutes. Remove from the heat and whisk in the egg yolks, salt, Essence and cheddar.
In a bowl with an electric mixer, beat the egg whites with a pinch of cream of tartar until stiff peaks form. Fold 1/4 of the egg whites into the cheese-egg yolk mixture. Gently incorporate the remaining egg whites. Spoon the batter into the tomato shells, filling them 3/4 full. Place the tomatoes in a baking dish, and sprinkle 1/2 teaspoon of dry jack cheese over each. Place the tomatoes in the oven and immediately lower the heat to 375 degrees F.
Bake until the soufflés have risen and are golden brown on top, about 20 to 25 minutes (but do not open the door during the baking time).
Remove from the oven and serve immediately.
Yield: 6 servings