Roughly chop the spinach into smaller pieces (about 1-inch pieces). This step is optional and can be skipped to make breakfast faster, but I prefer the smaller pieces that don't get stringy like whole spinach leaves can tend to be.

Crack the eggs into a large bowl, add a pinch of salt, and whisk (I prefer ribbons of white and yellow, but you can whisk until even if preferred).

Add the butter to a large skillet and melt over medium heat. Add the chopped spinach and sauté until the spinach has softened (2-3 minutes)

Push the sautéed spinach to the outside edges of the skillet and pour the eggs into the center. Gently fold the eggs as the bottom layer solidifies, until the eggs are about 75% solid. Fold the eggs into the sautéed spinach, then turn off the heat. The residual heat in the pan will finish cooking the eggs without overcooking or drying them out.

Top the eggs with the crumbled feta, a little freshly cracked pepper, and a pinch of crushed red pepper, then serve.