01 - Warm olive oil in a large, deep skillet or Dutch oven over medium heat.
02 - Add chopped shallot and minced garlic, sautéing until fragrant and softened, about 2 minutes.
03 - Incorporate the chopped greens gradually, stirring until slightly wilted before adding more.
04 - Pour in orange juice and vegetable broth, then season with sea salt, black pepper, and optional red pepper flakes.
05 - Cover and cook over medium-low heat for 12 to 15 minutes, stirring occasionally, until greens are tender yet vibrant.
06 - Remove lid, increase heat to medium, and cook for 2 to 3 minutes to evaporate extra moisture.
07 - Stir in most of the reserved orange zest, keeping some aside for garnish.
08 - Transfer to serving dish, sprinkle with remaining orange zest and toasted slivered almonds if desired, and serve warm.