Like a lot of showy Italian-inspired dishes, this cauliflower Parmesan comes together in a few steps, but the resulting casserole with tender breaded cauliflower smothered in homemade marinara, melty mozzarella, and handfuls of Parmesan is totally worth it.
This recipe is adapted from Melissa Clark for the New York Times.
To make the marinara, set a large, wide pot over medium heat. When hot, add the olive oil and then the onions. Cook, stirring often, 10 minutes. Add the garlic, tomato paste, salt, pepper, and pepper flakes, and cook 2 minutes more. Fold in the tomatoes, balsamic, and herbs (if using). Bring mixture to a boil, then turn heat down for a gentle simmer. Cook, stirring occasionally, for 30 - 45 minutes. As sauce cooks, add salt, pepper, and pepper flakes to taste.
Preheat the oven to 400 degrees F. Prepare a large rimmed baking sheet lined with parchment.
Cut the end off the cauliflower core and then slice into large, 3/4-inch thick florets that are 2- to 4-inches wide. Parts of the cauliflower that have the core attached will hold together best.
Working in batches, dip florets into egg mixture, let a bit drip off, and then dredge in the panko, pressing cauliflower into breadcrumbs on both sides.
Add 2 tablespoons oil to the skillet, and when shimmering, add a batch of cauliflower. Cook until golden and crisp. Flip and cook the other side. Remove cooked cauliflower to the prepared baking sheet. Repeat until all the cauliflower is cooked. As you cook, wipe burned bits of panko from the pan and add additional oil as needed, about 2 tablespoons per batch. Save little bits for the end, toss them in the egg mixture, dredge, and fry, shaking pan, until golden.
Spread 1 cup of marinara on the bottom of a deep 9 x 13-inch baking dish. Add half the cauliflower in a single layer (place the largest pieces in this layer). Top with 1/3 of the Parmesan, half the mozzarella, and 2 cups sauce. Add the remaining cauliflower, 1/3 of the Parm, remaining mozzarella, and another 2 cups sauce. Top with remaining Parmesan.
Bake until golden and bubbly, 40 - 45 minutes. Cool 10 minutes, top with fresh basil, slice, and serve.