Put eggs in a bowl and whisk with milk and melted butter.
Mix flour and salt in a large bowl.
Add liquid ingredients to flour and salt. Mix well and whisk until blended.
Add a knob of butter to a skillet over medium heat and cook about ⅓ cup (80 ml) batter at a time, about 90 seconds each side. Set aside.
Mix topping ingredients in a bowl.
Fill each crepe with spinach, onion and roasted pepper rings, crumbled feta, and avocado slices. Roll crepes up, drizzle with dressing, and sprinkle with chives.