Coat your salmon in the lime juice and cajun seasoning.
Prepare cauliflower rice according to the directions on the package. Cook the onions with olive oil for a minute and add paprika, cumin, chili flakes and some salt. Cook until the cauliflower is tender. Mix in the green onions and cilantro.
Remove the salmon fillets from the marinade and shake off slightly. Place in a hot skillet and cook for 3 minutes on each side, until blackened and crispy.
Serve over the cauliflower rice.