Step 1

Heat olive oil in a large, wide saute pan or skillet on medium high heat.

Step 2

Add mushrooms and saute for about 8-10 minutes, stirring occasionally until mushrooms begin to soften, brown, and are cooked through. Add salt and onion powder and garlic and cook for 1-2 minutes, stirring to ensure it doesn't burn.

Step 3

Turn down heat to medium and add spinach and turn with tongs until wilted (add in bunches if it all doesn't fit in the pan at once) Just before it's done, drizzle on balsamic vinegar and give a final toss.

Step 4

Plate and serve immediately.