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 2-2 ½ cups / 500 - 625ml water and salt. Bring to a boil, covered, reduce to simmer. Cook 20-25 mins checking after 10 minutes and adding ½ cup / 125ml 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.