Slice the red onion thinly.
In a large jar add rosemary sprigs, sugar, salt , peppercorns, garlic cloves,chili flakes, fresh ginger, vinegar.
Pour the hot water in the jar,making sure they're fully submerged.
Let sit at room temp for 30–60 minutes, and refrigerate for later use.
These can last 2-3 months max for best taste.
