Slow cooker Mexican chicken casserole

Ingredients
Serves: 4 

• 1 tablespoon olive oil
• 600g boneless and skinless chicken thighs
• 1 large red onion, cut into small thin strips
• 1 yellow pepper, cut chunky
• 1 red pepper, cut chunky
• 8 whole shallots, peeled
• 3 tablespoons honey
• 500g passata

• Spice mixture
• 1 tablespoon garlic granules or powder
• 1/2 tablespoon chilli powder
• 1/2 tablespoon ground cumin
• 1/2 teaspoon cayenne pepper
• 1/2 tablespoon sweet paprika
• 1/2 tablespoon ground black pepper
• 1/2 tablespoon sugar
• 1 teaspoon mustard powder
• 1 teaspoon ground coriander
• 1 teaspoon dried oregano
• 1 teaspoon dried thyme
• 1/2 teaspoon ground ginger
• 1 pinch cumin seeds
• sea salt to taste