01 -
Heat large skillet over medium-high heat. Add butter and olive oil, let butter melt.
02 -
Add mushrooms in single layer (cook in batches if needed), sprinkle with ¼ teaspoon salt. Cook undisturbed for 3 minutes until seared.
03 -
Flip mushrooms and cook 2-3 minutes more until browned, stirring minimally.
04 -
Reduce heat to medium-low. Add garlic and additional oil if needed. Add half the spinach, cover 30 seconds, stir, add remaining spinach, cover 30 seconds more.
05 -
Add remaining salt and lemon juice, stir to combine. Serve immediately.