Heat the oven to 500F.
Place the potato wedges on a baking sheet and drizzle about 3 tablespoons of EVOO over them. Add crushed garlic and season with rosemary, salt and pepper. Toss the potatoes to coat then roast 20-25 minutes until tender and golden at edges.
Once the potatoes have reached their halfway point, heat 1/4 of a cup of EVOO in a skillet over medium-high heat. Season the fish with salt and lots of black pepper.
Combine the cornmeal, flour, Parmigiano and lemon zest on a plate and coat the fish evenly. Add fish to skillet, skin side up, and cook until deeply golden brown, 7-8 minutes total, turning occasionally.
While the fish cooks, combine tomatoes, parsley, scallions, lemon juice and a drizzle of EVOO in a bowl. Season with salt and pepper.
Serve the fish with a little raw sauce on top and potatoes alongside.