To prevent the vegetables and polenta from sticking to the grill, be sure to lightly oil the cooking grate of your barbecue with vegetable or grapeseed oil.
For the polenta cakes:
6 cups water
2 cups Bob’s Red Mill coarse white or yellow polenta
1 tbsp salt
3 cloves garlic, minced
4-6 large Portobello mushrooms, destemmed
1. In a large mixing bowl, combine the oils, parsley and garlic for the marinade.
2. Distribute the marinade evenly over the mushrooms and let sit for 2-8 hours.
3. Before grilling, shake off excess oil from the mushrooms and save the marinade for later.
4. Add the mushrooms to the grill, cap side down, over medium-hot coals.
5. After 4-5 minutes, turn the mushrooms over, making sure to discard any liquid that has pooled in the caps of the mushrooms, and grill them on the stem side for another 4-5 minutes. Set aside.
6. Once they have cooled, slice the Portobellos into very thin strips.
To assemble to dish:
1. Once the polenta has cooled, cut it into 3″×3″ squares, lightly drizzle with olive oil, brush the grill with vegetable or grapeseed oil, then grill the polenta over very hot coals on both sides until crisp on the outside, about 5 minutes each side.
2. Slice each cake diagonally.
3. Toss some of the fresh arugula with the leftover mushroom marinade.
4. Place a few spoonfuls of pesto on a plate, then place two polenta cake pieces in the center and top with dressed arugula and strips of Portobello. Drizzle with more pesto if you like and season with salt and pepper to taste.