I roasted the cauliflower instead of steaming it, added roasted red pepper to the onions, and used less prosciutto, but otherwise did not change much else. I also like the yellow cauliflower, which gives a richer looking meal. I am tempted to try this with a mixture of yellow cauliflower and romanesco.
Added note (04/01/2018): I made this again fully vegetarian, and used 10 thin slices of hard tofu pan-fried to crispy edged in EVOO, garlic and Sriracha (Rooster Sauce). —Brian Coppola
head of yellow cauliflower, quartered
prosciutto (see tofu option), pan fried to crisp then chopped
1 x 2 x 1/8 in slices of hard tofu (vegetarian option), pan fried 5 minutes per side in hot EVOO with garlic and Sriracha (just to darken edges)
medium sweet onion, small chopped
roasted red pepper (12 oz jar), patted dry and small chopped
Place the cauliflower on a parchment-covered baking sheet. Drizzle with EVOO and roast at 450F for 20-25 minutes. Remove and cool to touch.
Partially caramelize onions in EVOO and 2T butter in a shallow pan, then add the red pepper and complete cooking. Set aside.
In a non-stick saucepan, combine 2T butter, feta, and garlic over medium heat. Add in 1 c of parmesan (or part/asiago), heavy cream, and the cheddar cheese. Blend thoroughly and heat to a light boil. Remove from the heat and let cool for a moment.
Chop the cauliflower (large) and line the bottom of an 8x8 baking dish, cover and blend with the cheese mixture.
Cover with a layer of the onion and pepper mixture, then distribute the prosciutto over the top.
Sprinkle with the remaining 0.5 c parmesan (or parmesan/asiago) cheese. Bake at 350F for 20 minutes.
Spoon into serving bowls. Sprinkle with freshly ground black pepper and a little loose parmesan.