Chicken biryani

Name: Chicken biryani
Ingredients: 2 tsp sunflower oil; 1 large onion, chopped; 300g skinless chicken breast, cut into chunks; 1 red pepper, chopped; 1 carrot, diced; 8 mushrooms, sliced; 1 aubergine, chopped into cubes; 1 tbsp curry paste (mild, medium or hot); 1 tbsp sultanas; 300g basmati rice, rinsed in cold water; 800ml boiling water; 100g frozen peas, defrosted; handful fresh coriander, chopped; 1 tbsp olive oil