Place the peppers cut side down onto a baking tray and place under a hot grill for 12-15 minutes, until the skins are completely black. Remove from the oven and place in a bowl, covering with cling film until cold.
Remove the blackened skin from the peppers then dice the flesh and reserve.
Preheat the oven to 180°C, 160°C fan, gas mark 4. Line a 12-hole muffin tin with paper cases.
Place the flour, half the grated Parmesan cheese and the mustard powder into a large bowl. Season with black pepper.
Whisk together the milk, eggs and melted butter, then pour the wet mixture into the dry and mix very lightly together.
Add the diced peppers and mix a little more, but do not over-mix.
Divide between the paper cases and top with the remaining grated Parmesan cheese.
Bake for 20-22 minutes, until golden. Remove from the tin and cool on a rack before topping with cream cheese, salt and pepper and a sprinkling of smoked paprika.