Stir-fry the beef with some cooking fat.
Cooking fat, 1 lb tender beef cut into thin strips
Remove the beef from the wok, make sure the wok regains its temperature, add more cooking fat and stir-fry the onion, ginger and garlic for about 3 minutes.
1 sliced onion, 2 minced garlic cloves, 1 tsp grated ginger
Return the beef to the wok and add the orange and lemon juice. Bring to a boil and add the spinach, lemon zest and orange zest.
1 tsp lemon zest, 1 tbsp lemon juice, 1 tbsp orange juice, A big bunch of spinach, 1 tsp orange zest
Cook the spinach until just wilted. Serve on a bed made with the segmented lemon and orange.
1 lemon, 1 orange