Step 1

1 Whisk together the soy sauce, sugar, vinegar, sesame oil, garlic, onion, sesame seeds, gochugaru and gochujang in a mixing bowl

Step 2

2 Divide equally between two gallon-size zip-top bags

Step 3

3 Add the chicken thighs to one bag; if you buy the thighs already boned, they might come rolled up; unroll them

Step 4

4 Add the squash, zucchini, onion and red bell pepper to the other bag

Step 5

5 Seal both bags and refrigerate for at least 4 hours or overnight

Step 6

6 Prepare the grill for indirect heat

Step 7

7 If using a gas grill, preheat to medium-high (450 degrees)

Step 8

8 When ready to grill, turn off at least one burner

Step 9

9 If using a charcoal grill, light the charcoal or wood briquettes; when the briquettes are ready, distribute them under half of the cooking area

Step 10

10 For a medium-hot fire, you should be able to hold your hand about 6 inches above the coals for 4 or 5 seconds

Step 11

11 Have ready a spray water bottle for taming any flames

Step 12

12 Just before cooking, grease the grate with a little vegetable oil

Step 13

13 Drain the marinade from the vegetables into a small saucepan; bring to a boil over medium-high heat for 3 to 5 minutes, then cool

Step 14

14 Discard the marinade from the chicken

Step 15

15 Place the chicken on the grill near the edge of the fire but not over it

Step 16

16 Place the onions on the grill farther from the flame

Step 17

17 Close the grill and cook for 5 minutes

Step 18

18 Use a spatula to carefully turn the onions over, taking care to not separate the rings

Step 19

19 Turn the chicken over and cook for 5 minutes on the other side

Step 20

20 Transfer the onions and chicken to a platter and let them rest while you cook the remaining vegetables

Step 21

21 Arrange those vegetables on the grill over direct heat; cook for 2 to 3 minutes per side, just to achieve grill marks

Step 22

22 Season with salt and pepper as needed

Step 23

23 Cut the grilled chicken, onions and vegetables into bite-size pieces

Step 24

24 Arrange them on a platter; serve with the reserved marinade as a dipping sauce