Preheat the oven to 400°F. Generously coat a rimmed baking sheet with nonstick spray and set it aside.

Trim the root end of the cabbage and position it upright on a cutting board with the flat end resting against the surface. Using a sharp knife, slice the cabbage from top to bottom into thick rounds, approximately ¾ to 1 inch in thickness. Arrange the slices on the prepared baking sheet, ensuring they do not overlap. If all the slices do not fit in a single layer, divide them between two baking sheets.

In a small mixing bowl, whisk together the olive oil, minced garlic, kosher salt, and black pepper. Brush one side of each cabbage steak generously with the seasoned oil, then carefully flip and coat the other side. Transfer to the preheated oven and roast for 26 to 28 minutes, or until the edges become crispy and caramelized while the center remains tender. If using a single baking sheet, place it on the center rack. For two sheets, position them on the upper and lower thirds of the oven. Rotate the pan(s) 180 degrees midway through cooking, and if using two sheets, swap their positions to ensure even roasting. There is no need to flip the cabbage slices. Any deeply browned or slightly charred outer leaves will add a wonderful depth of flavor.

While the cabbage is roasting, toast the pecans in the oven. Spread them out evenly on an ungreased baking sheet and place them in the oven alongside the cabbage. Toast for about 8 minutes, tossing halfway through, until they are aromatic and the inside of a broken pecan appears lightly golden. Keep a close watch during the final minutes, as nuts can burn quickly. Once toasted, immediately transfer them to a cutting board to cool before roughly chopping them.

Before serving, sprinkle the roasted cabbage steaks with freshly grated Parmesan cheese and a scattering of chopped herbs. Squeeze fresh lemon juice over the top for a bright, tangy finish, then garnish with the toasted pecans for added crunch. Serve hot and enjoy.