Dredge the tilapia filets in the arrowroot flour, and shake off excess. Set aside.
Melt ghee in a large skillet over medium-high heat. Once heated, add tilapia filets to the pan. Cook tilapia for 4 to 5 minutes per side. Remove cooked tilapia and set aside.
In the same skillet, reduce heat to medium-low and add diced jalapeño and minced garlic. Stir and cook for 2 minutes. Add spinach and cook until wilted. You might need to add spinach in batches.
Once spinach is wilted, add half of the diced tomatoes, salt, pepper and cashew milk. Increase heat to medium and continue stirring until sauce begins to simmer and thicken. Add in lemon juice, stir to combine and nestle cooked tilapia filets back into the skillet. Place a lid on the skillet and heat until sauce begins to simmer and filets are reheated.
Serve topped with reserved diced tomatoes and fresh-chopped parsley.