You first want to marinate the portobellos. Add the veggie broth, olive oil, steak sauce, liquid smoke, soy sauce and chopped garlic to a large freezer bag that seals really well.
Then place the portobellos into the bag, seal and shake around to coat the mushrooms completely. Lay them flat so they are submerged in the marinade. Marinate for at least 2 hours, but I like to leave them over night.
When you are ready to cook the mushrooms, preheat the oven to 425 degrees.
Remove the mushrooms from the bag and place them on a baking sheet. Then place the french fries on a separate baking sheet, because the mushrooms will get super juicy and you don't want the fries to soak in the juice.
Bake the mushrooms and fries at the same time. Bake the mushrooms for 20-25 minutes flipping halfway through baking. Check the directions on your fries for timing, but they most commonly will bake at 425 for about 20-25 minutes as well!
While the mushrooms and fries are baking, make the roasted red pepper chimichurri sauce. Add all the sauce ingredients to a blender or food processor. Blend until smooth. add a few pinches of salt and pepper. Taste and adjust seasoning.
Once the mushrooms and fries are done, serve immediately topped with sauce.