Cut each chicken breast in half lengthwise so you have four smaller chicken breasts. In a medium bowl, add the halved chicken breasts, olive oil, fresh lemon juice, Cajun spice, black pepper and salt together. Mix until combined and coat well.
Bring a large saucepan to a medium-high heat. Once the pan has reached temperature, sear the chicken breasts on each side for 2-3 minutes per side. Once the chicken is fully cooked through, remove from the saucepan and set aside to rest.
In the same pan, on medium-high heat, sauté the onions, garlic and chili until slightly caramelized (this delivers loads of flavour). Reduce the heat to medium and add the tomato paste. Sauté until the tomato paste has darkened in color and starts to stick to the base of the pan.
Meanwhile, bring a medium pot of salted water to a rolling bowl and cook the pasta for 7 minutes or until al dente. Note: remember to keep at least 1/2 cup of pasta water aside before draining the pasta.
Once the tomato paste has darkened, deglaze the pan with the vodka and cook for 2-3 minutes. Add the cream and allow to simmer for 1-2 minutes. Note: do not let the sauce reduce too much as you want a saucy pasta (see note 2).
Slice the rested chicken as you wish. Remove the sauce from the heat and add the sliced chicken and cooked pasta. Mix until everything's coated in the sauce. Salt to taste and allow the pasta to rest for 5 minutes before dishing up.
Whilst the pasta is resting, you can assemble the basic rocket salad as a garnish. Mix together the light brown sugar, white wine vinegar and olive oil. Lightly tear the rocket apart if it's too chunky, pour over the dressing and place a handful on top of each serving. Finish off with grated parmesan and your favourite chili oil or chili crisp and you're ready to stuff your face!