Easy Pickled Rhubarb.

Easy Pickled Rhubarb | Girl Versus Dough
Ingredients:
0.5 kg rhubarb stalks, trimmed to fit resealable jars
1.5 cups water
3/4 cup apple cider vinegar
1 tablespoon granulated sugar
1 tablespoon salt
Directions:
Tightly arrange rhubarb upright in resealable jars.
In medium saucepan, bring water, vinegar, sugar and salt to boil.
Cook 1 to 2 minutes, stirring until sugar and salt is dissolved.
Pour water-vinegar mixture over rhubarb in jars, leaving about ½-inch headspace at top of each jar (there may be leftover water-vinegar mixture).
Seal jars.
Chill 48 hours in refrigerator.
Store in fridge up to 1 month.

OR:
- Quick-Pickled Rhubarb With Lemongrass and Ginger | Serious Eats