Step 1

Heat 1 Tbsp. oil in a large saucepan over medium heat. Add onion; cook, stirring occasionally, until translucent, 3 to 4 minutes. Add mushrooms and garlic; cook, stirring occasionally, until the mushrooms release their liquid and begin to brown, 4 to 6 minutes. Add kale, tomato, and 1 tsp. herb mix. Cook, stirring occasionally, until the kale is wilted and the mushrooms are tender, 5 to 7 minutes. Stir in lemon juice and 1/4 tsp. each salt and pepper. Remove from heat, cover, and keep warm.

Step 2

Sprinkle fish with the remaining 1 tsp. herb mix and 1/4 tsp. each salt and pepper. Heat the remaining 2 Tbsp. oil in a large nonstick skillet over medium-high heat. Add the fish and cook until the flesh is opaque, 2 to 4 minutes per side, depending on thickness. Transfer the fish to 4 plates or a serving platter. Top and surround the fish with the vegetables; sprinkle with parsley, if desired.