Cover pistachios with filtered water in a small jar or bowl. Cover and refrigerate overnight. Drain water from pistachios.

Combine pistachios and fresh filtered water in a blender. Blend until smooth and creamy. Use cheesecloth or a fine-mesh strainer to strain pistachio milk. Discard the pulp or use in other recipes.

Heat milk in a saucepan over medium heat until steaming hot, about 3-4 minutes. Remove from heat and stir in honey and tea crystals. Pour into a mug and serve hot topped with frothed milk and chopped pistachios.