Combine chopped parsley with 1/4 cup of olive oil and salt. Whisk and set aside.
Heat a tablespoon of olive oil in a cast iron skillet. Sauté zucchini, squash, corn and pepper until tender and slightly browned, about 5 minutes. Add cherry tomatoes, and cook until soft. Remove from pan and set aside in a bowl.
Slice the polenta roll into circles about 1/2 inch thick. In the same pan, heat a tablespoon of olive oil, then cook polenta until slightly crisped, about 2-3 minutes per side. Remove from pan and drain on paper towel.
Toss arugula with lemon juice and 2 tablespoons olive oil. Top with radishes.
To serve, portion arugula salad into bowls. Top with polenta cakes, then vegetable mixture. Drizzle parsley and olive oil mixture on top. Enjoy!