Slow Cooker Chicken Tacos

Ingredients

• boneless, skinless chicken breasts
• yellow onion, sliced
• c. lime juice
• chiles in adobo, chopped, plus 3 tbsp. chiles in adobo sauce
• kosher salt
• packed brown sugar
• garlic powder
• chili powder
• cumin
• can Mexican beer, such as Modelo
• Corn tortillas
• Shredded purple cabbage
• Sliced jalapeño
• Sliced avocado