Curtido (El Salvadoran Cabbage Salad)

Combine the cabbage and carrot in a large bowl and pour the boiling water over the mixture. Allow the mixture to steep for 5 minutes; drain well. Return the cabbage and carrots to the bowl. Mix in the green onion, vinegar, 1/2 cup of water, and oregano. Toss until all ingredients are combined. Chill for 20 minutes before serving.