1. Marinate the Mushrooms:

> In a small bowl, whisk together 2 tablespoons of olive oil, balsamic vinegar, minced garlic, salt, and pepper. Brush this mixture over the portobello mushrooms and let them marinate for at least 30 minutes.

2. Prepare the Chimichurri

> In another bowl, combine the parsley, oregano, minced garlic, red wine vinegar, olive oil, red pepper flakes, and salt. Mix well and set aside for the flavors to meld.

3. Roast the Vegetables

> Toss the baby potatoes and asparagus with olive oil, salt, and pepper. Spread them out on a baking sheet and roast in a preheated oven at 425°F (220°C) for 25 minutes, or until golden and tender.

4. Grill the Mushrooms

> Heat a grill pan over medium-high heat. Grill the marinated mushrooms for about 5 minutes on each side, or until they are tender and have nice grill marks.

5. Serve

> Serve the portobello mushrooms with a vibrant herb chimichurri sauce and served alongside roasted baby potatoes and asparagus.