Season salmon with kosher salt and fresh ground pepper and place in pre-heated cast iron skillet with olive oil for 5 minutes depending on fillet thickness. Flip and continue to cook for 2 minutes. Remove from skillet and set aside.
Wipe skillet and melt butter. Add cherry tomatoes. Cook for two minutes and add spinach until wilted.
Add in cream and season to taste.
Place salmon fillet back in skillet and let cook for 2-3 minutes or until everything is heated through.