In a medium saucepan, heat the vegetable broth and water until simmering. Add the tea bag and let steep for 5 minutes, then remove the bag and keep the broth warm. Tip: Use a fine-mesh strainer if tea leaves escape.

Heat olive oil in a large skillet over medium heat. Add the onion and sauté until translucent, about 3 minutes. Add garlic and cook for 1 minute until fragrant. Tip: Stir frequently to prevent burning.

Add the mushrooms and thyme, cooking until the mushrooms release their moisture and brown slightly, about 5 minutes. Tip: Don’t overcrowd the pan for better browning.

Stir in the barley and soy sauce, coating the grains with the oil and vegetables. Cook for 1 minute. Tip: Toasting the barley enhances its nutty flavor.

Begin adding the warm broth, one ladle at a time, stirring frequently. Allow the liquid to absorb before adding more, about 20-25 minutes total. Tip: Keep the heat at a gentle simmer.

Once the barley is tender and creamy, stir in Parmesan and butter (if using). Season with salt and pepper to taste. Tip: For a vegan version, skip the cheese and butter.