Gather all your ingredients on the countertop. Make sure you're equipped with a mixing bowl, a sturdy spoon, and a sharp knife for dicing the apple. Having everything ready will streamline the process. I often find that organization makes cooking so much more enjoyable.

In a large bowl, combine the raisins, currants, sultanas, and candied peel. Give it a good stir, allowing the fruits to mingle. This is your fruit base, which will give your mincemeat a delightful sweetness.

Add in the finely diced apple to the fruit mixture. The apple adds texture and a slight tartness that balances the sweetness. Stir it well, ensuring that the apple’s juices start to blend with the other fruits.

Now, sprinkle in the dark muscovado sugar, ground cinnamon, and mixed spice blend. This step is where the magic begins. The sugar will help draw out the moisture from the fruits, enhancing their flavors.

It's time to pour in the brandy, lemon zest, lemon juice, and vanilla extract. Make sure you mix everything thoroughly, letting the ingredients really combine. The alcohol will cook down nicely in your baked goods, adding depth that enhances the overall profile of your dish.

Finally, add the chopped walnuts and vegetarian suet into the mix. These ingredients contribute a lovely texture and enhance the richness of the mincemeat. Combine everything gently – you want an even distribution without mashing the fruits.

For the best results, let your mincemeat sit for at least an hour before using it. This resting time allows the flavors to develop, making it even more delightful. But if you’re in a hurry, it’s still delicious right away!