Preheat the oven to 190°C/170˚C fan/375°F/Gas Mark 5. Add the flour, baking powder,, cheddar, halloumi, sweetcorn and chives a little of the chopped jalapeno into a bowl.
Add polenta, season with salt and black pepper and stir to combine.
In a jug, mix together the milk, eggs and melted butter.
Line a large muffin tin with paper cases - or, grease a large silicone muffin tray. Add the wet ingredients into the dry ingredients and stir to only just combine, then spoon the mixture into the muffin tin.
Top all the muffins with a sprinkle of cheddar cheese and press a slice of jalapeño into half of the muffins to give them a little kick of heat.
Bake the muffins in the oven for 20 minutes, or until golden and risen. Leave to cool before assembling with the rest of your bento box fillers.