When a dish needs a vibrant, last-minute flavor lift, reach for this Hanoi-style condiment. At the table, sprinkle it into noodle soup, pan-fried and stir-fried noodles, and fried rice. At the stove, splash it into sautéed or stir-fried greens.
Stir together all ingredients in an airtight container. Cover and refrigerate 8 hours or overnight before checking for flavor.
Check for flavor: It should mainly taste of garlic, with chile playing a minor supporting role. If either flavor is harsh, add more vinegar and water, starting with a 1-to-2 ratio. Increase or decrease amount of garlic, depending on its pungency and your preference. For extra chile bite, double the quantity, and see what happens. Taste it 1 day after it’s made, and keep tinkering to get a formula you like.
Refrigerate in an airtight container for months. When the vinegar runs out, add new ingredients to the jar. When things taste tired or off, start over.