To make the peri peri sauce, remove the seeds from the bird eye chillies, and add them to a mini food processor with the garlic. Blitz until finely chopped. Add the lemon juice, white wine vinegar, olive oil, honey, and a pinch of salt and pepper, and blitz thoroughly until the sauce becomes orange.
Place the portobello mushrooms in a lightly oiled griddle pan, and cook over a medium-high heat for a few minutes each side, until nearly soft.
Cut the halloumi into around 6 slices (thicker slices tend to work better), and add to the pan with the mushrooms. Spoon a little of the peri peri sauce over the halloumi and mushrooms, and when the halloumi is golden brown underneath, turn everything over and add more peri peri sauce. You may have a little sauce left over - just keep it in the fridge until its next use.
Serve the peri peri halloumi and portobello mushrooms in crusty bread rolls, with creamy salad dressing (to counteract the heat!) and salad leaves.