Pickled beetroot and sweet mustard pickles

I've been harvesting a lot from the garden lately and the excess, as usual, is either frozen or pickled. I did up a nice batch of beetroot last week and still have another batch in the ground to process later this week. Beetroot is delicious juiced, grated and eaten raw, or roasted and served with other root vegetables - either hot or in a warm salad. These beetroot were boiled, then sliced and