1. Several hours ahead of time, marinate your seafood and vegetables. Divide the buttermilk between two large resealable plastic bags. Place the shrimp in 1 bag and the sliced squash, onion, and okra in the other. Transfer to the refrigerator to chill for at least 2 hours.

2. Closer to serving, make the marinara: Pour the entire can of tomatoes into a large saucepan, then place over medium heat. Bring to a simmer and cook for at least 15 minutes, then add the basil, garlic, butter, and salt and pepper to taste. Remove the pan from the heat. Transfer the tomato mixture to a blender or food processor and pulse until blended. Set aside.

3. Once the shrimp and veggies are marinated, set up your dredging and frying stations. In a large, shallow dish, mix together the cornmeal and seasoned flour. Fill a large, heavy-bottomed skillet with about an inch of oil, then heat over medium-high heat.

4. Once the oil is hot, start frying the vegetables first. Working in batches so you don’t overcrowd the pan, remove the vegetables from the buttermilk, then dredge in the dry mixture and carefully add to the oil. Fry until very browned, then immediately transfer them to a wire rack or paper towel–lined sheet tray to drain. Season with salt.

5. Once you’ve fried all the veggies, repeat the same process with the shrimp, dredging it in the dry mixture, then frying it in the oil. Immediately transfer the shrimp to a wire rack or paper towel–lined sheet tray to drain. Season with salt.

6. Place everything in a large serving bowl and serve hot with sliced lemons and marinara on the side for dipping.