Boil a large, salted pot of water for the pasta. Cook until al dente (according to package instructions), reserving some of the pasta water (60-80 ml).
Meanwhile, using a large non-stick skillet, heat the oil and butter over medium-high heat. Add the chicken, season with salt and pepper and fry for 3-4 minutes, until cooked through. Remove from pan and set it aside.
Reduce the stove's heat to medium. Add the garlic and the red pepper flakes to the skillet and sauté for 30 seconds, until the garlic is fragrant. Add the sun-dried tomatoes, and Dijon mustard and cook for another 30 seconds, stirring constantly.
Add the crème fraîche, seasonings and lemon juice to the pan. Stir until the sauce is smooth.
Return the chicken to the pan along with a little pasta cooking liquid (until sauce is desired consistency (ca. 60 ml). Let it cook for one more minute. Stir in the baby spinach (if using) and add the pasta. Toss to combine.
Transfer into serving bowls and garnish with fresh basil. Serve with grated parmesan on the side. Enjoy!
Notes
I like short pasta for this recipe, like rigatoni, volanti (seen here) or orecchiette.
Cajun seasoning is made from paprika, chili or cayenne, thyme, oregano, powdered garlic and onion. Sometimes cumin as well. If preferred a store bought cajun mix can be used rather than the seasonings in this recipe.