1. Fill a large stockpot with water; bring to a boil. Cut cauliflower into 1/2-inch pieces. Add cauliflower to boiling water, cooking until fork-tender. Drain; set aside. 
2. In another saucepan, melt butter over medium heat. Add flour, whisking to combine. Slowly add milk while whisking. Bring to a simmer; allow to thicken for about 5 minutes. Remove from heat, and stir in Swiss cheese. Season with salt and pepper. Let cool for 10 to 15 minutes. 
3. Using a 12-cup muffin pan, line the cups with prosciutto. In a small bowl, whisk the egg. Add a large spoonful of cheese sauce to the egg. Stir to combine. Pour egg mixture into rest of sauce. Add cauliflower to sauce. Stir to completely coat and combine.
4. Preheat oven to 400° F. Spoon cauliflower mixture into lined muffin cups. Sprinkle the tops with parmesan. Bake for 20 minutes until edges are slightly brown and cauliflower mixture is slightly firm. Allow to cool for 10 minutes before carefully removing the cups from the pan.

Calories: 133, Fat: 8 g (4 g Saturated Fat), Cholesterol: 47 mg, Sodium: 521 mg, Carbohydrates: 5 g, Fiber: 1 g, Protein: 11 g.