For the pasta, heat a frying pan until hot over a medium heat, add the fresh cherry tomatoes and fry for 4-5 minutes, or until just softened. Remove from the pan and set aside.
Add the olive oil, red onion, garlic and chilli to the pan the tomatoes were cooked in and fry for 2-3 minutes.
Add the halloumi cheese and cook for 1-2 minutes on each side, or until pale golden-brown on both sides. Add the canned cherry tomatoes and bring to the boil, then reduce the heat and simmer for 2-3 minutes. Add the fresh cherry tomatoes and oregano and cook for a further minute. Season, to taste, with salt and freshly ground black pepper.
Add the cooked pasta to the pan and mix gently until well combined.
For the salad, whisk the mustard and vinegar together in a bowl, then whisk in the olive oil. Season, to taste, with salt and freshly ground black pepper.
Place all the salad leaves into a bowl and pour over the dressing. Stir until well combined.
To serve, spoon the pasta onto four serving plates and sprinkle over the grated parmesan. Spoon the dressed salad alongside.