Begin by washing and slicing the carrots, cucumber, radish, and onion into thin matchsticks. Arrange the vegetables in a clean bowl.

In a medium saucepan, combine equal parts water and vinegar over medium-high heat. Bring to a boil, stir in garlic, sea salt, sugar, oregano, and green onion, and dissolve completely.

Pack the sliced vegetables into a clean mason jar and pour the cooled brine over them, ensuring they are fully submerged.

Let the jar cool at room temperature for about 20 minutes, then refrigerate. Enjoy them within two weeks for the best taste!