Loaded Veggie Sandwich with Sweet Pickled Red Onions

1. Prepare the pickled red onions: In a saucepan, combine 1 cup water, 1 cup distilled white vinegar or red wine vinegar, 2 tbsp sea salt, and 2 tbsp sugar. Bring the mixture to a simmer, then immediately remove it from the heat.
2. Meanwhile, slice one large red onion (or two medium onions) and add the slices to an airtight container. Add 2 cloves of garlic to the container.
3. Pour the hot brine over the sliced red onions and garlic in the container. Once cooled to room temperature, seal the container and place it in the fridge. The pickled red onions can be used within 30 minutes, but will keep for up to a week.
4. To assemble the sandwich, toast two slices of sourdough bread.
5. Spread garlic hummus on one half of the toasted sourdough.
6. Spread pesto on the other half of the toasted sourdough.
7. Layer the cucumber, sliced avocado, heirloom tomato, sweet pickled red onions, lettuce, and sprouts on the sandwich.