Keep a batch of these pickled onions in your fridge every week. For variations, consider using apple cider vinegar, or swapping sugar for honey, maple syrup, or a sugar substitute. You can also add 5-6 whole peppercorns, 0.5 tsp mustard seeds, 0.25 tsp red pepper flakes, or a bay leaf to the jar. For spicy onions, add a few slices of jalapeño or a pinch of red pepper flakes. For herb-infused onions, tuck in fresh dill sprigs or thyme. Ensure onions are very fresh for the best crunch; avoid boiling them directly in the brine. If onions are not fully submerged in the jar, gently press them down with a small fermentation weight or a small plate.