Southern-style collard greens get their signature richness from being braised with ham hocks or bacon. For a meatless flavor boost, use an umami-packed Parmesan rind instead (find one made without rennet for a strictly vegetarian version). The rind will hold its shape as the greens simmer, so you can remove it from the pot in one piece when done.

1 Parmesan rind (3 to 4 inches long)

3 pounds (about 4 bunches) collard greens, stalks removed, leaves cut into 1-inch pieces

Pinch red-pepper flakes, or more to taste

3 tablespoons white-wine vinegar

Kosher salt and freshly ground pepper

Hot sauce, for serving (optional)

In a large pot, combine Parmesan rind, collard greens, red-pepper flakes, and 8 cups water; bring to a boil. Reduce to a simmer, and cook until collards are very tender, 45 minutes to 1 hour.
Remove Parmesan rind, and discard. Add vinegar, and season with salt and pepper. Serve collards with their broth, and, if desired, hot sauce.