Rinse the asparagus in cold water and trim off tough ends of stalks. Heat the ghee and olive oil together in the cast iron skillet, over a medium heat. Add the asparagus to the pan, shaking the pan gently to coat the asparagus in the melted ghee and olive oil.
Cover tightly and cook over medium heat for 3 to 4 minutes. Check the asparagus and turn as needed to make sure the stalks cook evenly and don't burn too much on one side. Uncover.
Continue cooking 5 minutes longer uncovered, or until asparagus is tender but still crisp but still a nice bright green with a few blistered and burnt spots (Don't overcook). Add the garlic and lemon zest right at the end. Remove from the heat. Give it a toss. Season to taste with salt and pepper and serve hot.
Serve with fresh lemon wedges.
Notes
Pencil thin asparagus will cook way way too quickly using this method, best to look for more medium-sized stalks. Add some toasted nuts or breadcrumbs at serving, for a little extra crunch.