Sheet pan steak fajitas

Ingredients

• 1 1/4 lb skirt steak
• 1/4 cup canola oil , divided
• 2 tbsp reduced-sodium soy sauce
• 2 tbsp fresh lime juice
• 1 tbsp chili powder
• 1 tbsp finely chopped garlic
• 1 1/2 tsp packed brown sugar
• 1 tsp ground cumin
• black pepper
• 1/2 tsp salt , divided
• 1 medium red onion , cut in 3/4-in. wedges through root
• 1 red bell pepper , seeded and quartered
• 1 green bell pepper , seeded and quartered