Preheat oven to 400°F. Generously coat a baking sheet with cooking spray. Set aside.
Prepare the cauliflower steaks: Remove any leaves from cauliflower, but leave the core and stems intact. With the heads stem-side up, use a large chef’s knife to cut each through the stem to create two equal halves. Cut a 1-inch-thick slice from each half, using the part with the stem. You’ll have extra cauliflower left over; use as cauliflower rice or crudités.
Line up three shallow dishes. Put cornstarch in dish one, the beaten egg in dish 2 and the panko, parmesan, salt and pepper in the third.
Dredge each side and the edges of each cauliflower steak in the cornstarch, shaking off any excess, then dip them in the egg and let any excess drip off. Lastly, press each side and the edges into the panko mixture. Place on the prepared pan and generously spray both sides of the cauliflower with cooking spray.
Bake, flipping the cauliflower and rotating the pan from front to back halfway through, until the cauliflower is tender and the coating is toasted and crispy, 45 to 55 minutes. Allow cauliflower to rest on the baking sheet while ragout is prepared.
Heat 1 1/2 Tbsp oil in a medium skillet over medium-high heat. Add tomatoes and cook, shaking the skillet occasionally, until they just start to burst, about 3 minutes. Add wine and cook until reduced by half, about 2 minutes. Stir in beans, garlic, crushed red pepper and season with salt; cook another 2 minutes then remove from heat.
To serve: Place one cauliflower steak on a serving dish. Spoon the bean ragout over the top and sprinkle with fresh herbs. Finish by drizzling each dish with about a half tablespoon of the Tuscan Herb oil.