Heat a sauce pot over medium heat with a drizzle of olive oil. Gently cook mushrooms 5 minutes, season lightly with salt and pepper. Add a splash of sherry and cook off. Add beef stock and 1 cup water and simmer over low heat.
Whisk eggs in a bowl with a pinch of salt and a splash of water, about 2 teaspoons. Sprinkle the flour while you whisk and add a dash of freshly grated nutmeg. Heat a drizzle of olive oil at a time in a small nonstick pan over medium-high heat. Add a small ladle of eggs to the pan and swirl it around. Flip the egg crepe after 30 to 40 seconds and cook 15 to 20 seconds on the other side. Stack up the egg crepes and when you've used the last, 6 to 8 crepes, roll the crepes and slice into 1-inch strips.
Divide the crepe strips evenly among 4 bowls and top with 2 tablespoons chopped chives then ladle the beef and mushroom broth over top and serve immediately.