To roast the capsicum, pre-heat your oven to 200 degrees Celsius. Place the capsicum cheeks on a baking/oven tray, skin side up and lightly spray with olive oil.
Place in the oven for 15-20 minutes or until the skins have started to go black. Remove from the oven and immediately place in a sealed container to cool. Sealing them as they cool will cause the capsicums to sweat and make removing the charred skin much easier.
Once the capsicum cheeks are cool enough to touch, peel away the skin and set the flesh aside to pop in your sandwich.
To grill the haloumi, heat a small, non-stick pan over medium-high heat. Add the sliced haloumi and cook until lightly golden for about 2-3 minutes. Flip over and cook the other side until golden. Remove from the heat and set aside.
Meanwhile, spread one side of your bread roll with the hummus. On the other side of your bread roll, place the grilled haloumi slices, roast capsicum flesh, sliced tomatoes, baby spinach and red onion slices. Top with the other half of your bread roll and serve. Enjoy!