Oven-baked mushroom and chicken brown rice risotto

Ingredients

• 1 tablespoon oil
• 350 grams boneless chicken, diced
• 1/4 cup dried shiitake mushrooms
• 5 cups chicken stock, hot
• 1 onion, chopped
• 3 cloves garlic, crushed
• 350 grams portobello mushrooms, sliced
• 1/2 teaspoon dried thyme or several fresh thyme sprigs
• 2 cups brown rice
• salt and black pepper
• 1/2 cup grated parmesan cheese
• 1 teaspoon lemon zest
• fresh seasonal greens, to serve (optional)