Preheat oven to 350F
Line a sheet pan with parchment paper. Pan should be a minimum 15 ½ “x 10”. In fact, the larger the better. You want to be able to spread your ingredients out so they cover the pan in one layer for more even cooking.
Slice peppers into same size strips
Slice onions into same size strips (similar to peppers) slicing top to bottom.
In a bowl toss peppers, onions, 2 tablespoons of the oil, 1 ½ teaspoons of the chili powder, 1 ½ teaspoons of the garlic powder, salt to taste and fresh ground pepper to taste, making sure strips are well coated.
Spread seasoned vegetables out on sheet pan and place in oven for 15 minutes
While those cook, cut chicken breasts into strips, long-ways. If breasts are too thick butterfly so pieces are thinner. Make sure strips are similar in size.
In a bowl toss chicken strips with remaining oil, chili powder, garlic powder, salt and pepper.
Pull sheet pan out of oven, and with a spatula or tongs, push vegetables to one side, covering about half of the sheet pan. Spread seasoned chicken strips over the other half of the sheet pan, and place back in oven for about 20 more minutes, tossing chicken as well as vegetables for even cooking. Chicken strips should reach internal temperature of 165oF. Vegetables should be tender, not mushy.
When cooked, transfer the peppers to a bowl and the chicken to a separate bowl.
Sprinkle some cilantro, cotija (if using) and lime over the chicken.
Plate some arugula. Layer on some onions and peppers. Top with the chicken and enjoy.