Soak the raisins and currants in the cold tea overnight (at least 8 hours).

Preheat oven to 350F (175C).

Line a 1 lb loaf pan with greased parchment paper.

In a large bowl, combine the soaked raisins and currants with the tea.

Add the light brown sugar, self-rising flour, egg, mixed spice, crystallized cherries, and candied peel to the bowl.

Stir all ingredients together until well combined.

Pour the batter into the prepared loaf pan.

Bake for approximately 1 1/2 hours, or until a toothpick inserted into the center comes out clean.

Let the loaf cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.

Store the Barm Brack in a covered tin to keep it fresh.

Serve buttered.