One Pot Broccoli, Chicken and Rice Casserole

Name: One Pot Broccoli, Chicken and Rice Casserole
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: European, American, Italian, Mediterranean
Ingredients: 2 tbsp (30g ) unsalted butter; 1 tbsp olive oil; 1 onion (, finely chopped); 2 garlic cloves (, minced); 500g (1 lb) chicken thigh (, cut into bite size pieces (Note 1)); 2.5 tbsp flour ((or 1 ½ tbsp. cornflour / cornstarch)); 2 cups (500 ml) milk ((any, I use low fat)); 2 cups (500 ml) chicken broth; 1 1/4 cups (225g) long grain white rice (, uncooked (Note 2)); 1 tsp dried thyme (or other herb of choice); Salt and pepper; 1 large head of broccoli, broken / cut into small florets (~400 - 500g / 14 oz - 1 lb) ((Note 3)); 2 cups (200g) shredded mozzarella or cheddar ((or other cheese of choice) (Note 4)); Finely chopped parsley (, optional garnish)