Cover millet with water and apple cider vinegar, soak 8 hours or overnight.
Drain and rinse the millet. Add to a medium pot over medium-high heat to toast the grains (optional) until fragrant.
Once fragrant and toasted, add 2½ -3 cups / 625 - 750ml water and salt. Bring to a boil, covered, reduce to simmer. Cook 20-25 mins checking after 10 minutes and adding ½ -1 cup / 125 - 250ml water if the pot becomes too dry.
Fluff with a fork and serve. Enjoy warm or cold. Store cooled leftovers an airtight container in the fridge for up to 5 days.