Chilli Cornbread Pie

Ingredients

• 4 tablespoons sunflower oil
• 1 large onion, finely chopped
• 2 garlic cloves, finely chopped
• 450 g (1 lb) lean minced beef
• 2 x 400-g (14-oz) cans chopped tomatoes
• 2 x 400-g (14-oz) cans chilli beans
• 150 g (5 oz) cornmeal or quick-cook polenta
• 150 g (5 oz) self-raising flour
• 2 teaspoons baking powder
• 2 eggs, lightly beaten
• 300 ml (1⁄2 pint) buttermilk or Greek yoghurt
• salt
• freshly ground black pepper
• mixed green salad, lightly dressed, to serve