Season chicken with salt, pepper, paprika and onion powder.
Heat 2 tablespoons of the reserved sun dried tomato oil in a large skillet over medium-high heat. Sear the chicken for 6-8 minutes each side, or until golden and cooked through (work in batches if your pan isn't large enough). Transfer to a warm plate; set aside.
Add the remaining oil into the pan and fry the garlic until fragrant (about 30 seconds to 1 minute), then add in the sun dried tomatoes. Fry for 1-2 minutes to release their flavours. Mix the Dijon through all of the flavours.
Reduce heat to low-medium heat, add the cream (or evaporated milk) and bring to a gentle simmer, while stirring occasionally. Season with salt and pepper to your taste.
Add in the spinach leaves and allow to wilt in the sauce, then add in the parmesan cheese. Allow sauce to simmer for a further minute until cheese melts through the sauce.
Add the chicken back into the pan; top with parsley and serve over pasta, rice or steamed veg.