Begin by heating a large skillet over medium-high heat and adding a tablespoon of neutral oil, allowing it to shimmer and smell slightly nutty.
Add the sliced mushrooms to the hot skillet and cook, stirring occasionally, for about 4-5 minutes until they darken and release a fragrant aroma. They should turn a deep brown and become slightly crispy on the edges.
Push the mushrooms to one side of the skillet, then add a teaspoon of oil if needed and toss in the minced garlic. Cook for about 30 seconds until fragrant and golden, stirring constantly to prevent burning.
Add the shrimp in a single layer to the empty side of the pan. Cook for 2-3 minutes until the shrimp turn pink and opaque, then flip and cook for another 1-2 minutes until fully done. The shrimp should jiggle slightly but be firm and pink throughout.
Squeeze the fresh lemon juice over the shrimp and mushrooms, tossing everything gently to coat and bring brightness to the dish. Let cook for another minute until the sauce becomes glossy and fragrant.
Remove the skillet from heat and sprinkle with chopped herbs and chili flakes if using. Give everything a final gentle stir to incorporate the herbs and flavors.
Transfer the shrimp with mushrooms to a serving plate, spooning any remaining sauce over the top. Serve immediately while hot, garnished with extra herbs or lemon zest if desired.