Warm Kobe Beef with Truffle Tea

Name: Warm Kobe Beef with Truffle Tea
Ingredients: 8 ounces Kobe beef; 2 cups white mushrooms, chopped; 1 cup portobello mushrooms, chopped; 1/2 yellow onion, chopped fine; Vegetable oil, for sauteing; 2 Idaho potatoes, peeled and diced; 1 teaspoon olive oil; Salt and pepper, to taste; Garnish: 2 sprigs thyme; 2 cups dried shiitake mushrooms; 1 cup dried citrus tea leaves; 1 quart water; 1 shallot, chopped; 1 stalk lemon grass; 1 (3-inch) piece of ginger; 1 cup Bonito flakes; 2 tablespoons soy; 1 sheet kelp; 1/2 cup sherry; 1 to 2 teaspoons truffle oil (1 drop in each cup before serving)