Preheat oven to 450 degrees. Line a baking sheet with parchment paper.

Prepare the sauce by blending the cottage cheese with the lemon juice, mustard, chives, hot sauce and a large pinch of salt and pepper until smooth – you may have to scrape down the sides of the blender 2 or 3 times to get it really smooth. Place in a small serving bowl and set aside. (If you make the sauce ahead, refrigerate it.)

Separate the eggs putting the whites in a large mixing bowl and the yolks into 4 small bowls (one yolk in each bowl). Beat the egg whites until glossy, stiff peaks form. Gently fold in the spinach, ham, Parmesan cheese and a large pinch of pepper.

Spoon the mixture into 4 mounds on the parchment paper, making a deep well in the center of each. Bake for 3 minutes then slide 1 yolk into each well. Sprinkle with a small pinch of salt and pepper and bake until the yolks are set, 3 - 4 more minutes (a minute or two longer if you don’t like the yolks runny).

Serve immediately with the sauce on the side.