Jangajji (Korean Soy Sauce-Pickled Vegetables and Chiles)

Ingredients

• 1 cup distilled white vinegar
• 3/4 cup soy sauce
• 1/4 cup maple syrup
• 3 tablespoons fish sauce
• 1/2 large yellow onion , cut into 1 1/2- to 2-inch pieces
• 6 medium garlic cloves , halved lengthwise
• 4 ounces moderately hot chiles such as jalapeños or Italian long hot chiles, stemmed and sliced into 3/8-inch-thick rounds (about 1 cup)
• 4 ounces mild chiles, such as green asagi gochu Korean chiles, shishitos , or Jimmy Nardellos, stemmed and sliced into 3/8-inch-thick rounds (about 1 cup)
• 4 ounces chayote squash, kohlrabi, or daikon radish , peeled and cut into 1- by 1- by 1/2-inch pieces (about 1 cup)