Preheat the oven to 350°F and line a muffin tin. Alternatively, lightly grease the holes of the muffin pan, then press a 5in square of baking paper into each hole, shaping the squares to fit by folding the sides.
Put the pine nuts in a dry, non-stick pan over a medium heat for a few minutes, shaking and tossing the pan continuously until they start to turn golden. (Don’t leave them in the pan or they will quickly burn.) Tip them out onto a plate to cool.
Mix together the flour, baking powder and polenta in a mixing bowl. In a separate bowl, lightly mix together two-thirds of the cheese and all the remaining ingredients.
Pour the wet ingredients into the dry ingredients and mix quickly and lightly to form a lumpy batter. (Overmixing will make the cooked muffins turn out heavy.) Spoon into the prepared muffin cases and scatter the remaining cheese over the top. Bake for 20 minutes until risen and golden.
Leave to cool in the pan for a few minutes, then transfer to a wire rack. Serve warm or cold.