Sauté shallots in a large saute pan, generously coated with evoo, over medium heat, until the edges are just beginning to caramelize and turn golden brown.
Add mushrooms and continue cooking, stirring occasionally until mushrooms are deep golden brown and have crispy edges, about 10 minutes.
Add garlic and stir for just another minute to soften garlic a bit. Add balsamic and stir to coat mushrooms.
Divide arugula between 5 to 6 plates, top with warm mushrooms and drizzle with pan juices.
NOTES FROM THE TEST KITCHEN:
Turn the delicious salad into a WOW by adding: toasted hazelnuts, pistachios, or pine nuts, sundried tomatoes, shaved parmesan and Asiago cheeses (for dairy meals)