1. Wash and thoroughly dry all vegetables. Cut the broccoli into bite sized florets, slice the bell peppers into strips, slice the mushrooms, and thinly slice the onion.

2. Heat the olive oil in a large skillet over medium high heat until the oil is hot and shimmering.

3. Add the broccoli and onion to the skillet and sauté for 3 to 4 minutes, stirring often, until the broccoli turns bright green and the onion begins to soften.

4. Stir in the sliced bell peppers and mushrooms. Cook for another 5 to 7 minutes, stirring occasionally, until the vegetables are tender crisp with light browning on the edges.

5. Add the minced garlic, Italian seasoning, salt, black pepper, and red pepper flakes if using. Cook for 30 to 60 seconds, stirring constantly, just until the garlic is fragrant.

6. Turn off the heat and drizzle the lemon juice over the vegetables. Toss well to coat and taste, adjusting the seasoning if needed.

7. Sprinkle with chopped fresh parsley and serve the sautéed vegetables hot as a side dish or over rice, quinoa, or your favorite grain.