Heat olive oil in a large skillet over medium heat.
Add onion and garlic; cook until soft, about 5 minutes.
Stir in chopped mushroom and pepper flakes; cook until mushroom is coated with oil and begins to soften.
Add sherry and chicken broth; simmer until liquids reduce by half.
Add arugula; cook until wilted, about 1 minute.
Season with black pepper. Serve immediately.
Serving Suggestions
Top with crumbled feta
