Warm your non-stick pan over medium heat while you prepare the batter.
Whisk together flour, milk, eggs, melted butter, and salt until perfectly smooth; allow this to rest for at least 30 minutes for the best texture.
Lightly butter or spray your skillet to prevent sticking before cooking.
Pour about 1/4 cup of batter into the skillet and tilt it quickly to spread a thin layer.
Cook the crepe for 1 to 2 minutes until the edges lift, then carefully flip and cook the other side for about a minute.
Stack finished crepes on a plate separating each with parchment paper to avoid sticking.
Fill each crepe gently with scrambled eggs, sautéed spinach, shredded cheese, and diced tomatoes, then fold or roll them up.
Sprinkle chopped chives over the crepes and serve warm, optionally adding sour cream or hot sauce if desired.
