Chicken, Broccoli and Cauliflower Gratin

(If you know me at all, you know I don’t measure when I cook…so as always, these are all fairly rough but somewhat educated guesses on the amounts of each ingredient I used. And I used the same large pot for all of these steps because that’s just how I cook…but if you’re anything like my husband you may use 3 or 10 different pots and pans, I’ll never know…)
-Cut the florets off 1 head of cauliflower and 2 bunches of broccoli (about equal amounts of each)
(*Thinly slice some of the more tender parts of the broccoli stalks as well, these are edible and delicious so don’t waste them)
-Cut the florets into bite-size pieces and blanch them in heavily salted water with a few lemon peels until almost fork tender. Shock them in a large bowl of ice water to stop the cooking process. Set aside.
-Cut 3 boneless, skinless chicken breasts into bite-size chunks and season all over with s&p, dried thyme, sage and rosemary. Brown in olive oil but don’t cook through. Set aside.
-Dice 1 large onion and saute in the reserved oil from the chicken, you may need more oil…
-Season with s&p and a pinch of sugar.
-When the onion is translucent add 1 TB of butter and melt. Add 3 heaping TB of flour and whisk until there are no lumps. Add 1/4 cup white wine and whisk until bubbly. Add 1 cup each of milk and chicken stock and whisk again until everything is combined. Add 2 TB of dijon mustard and several good gratings of fresh nutmeg. Allow this mixture to come up to a bubble and begin to thicken a bit. Add 1/2 lb of grated cheese (*I used a Spanish cheese called ‘Iberico’ which is a sheep, goat and cows milk cheese but a combination of asiago, gruyere and chevre cheeses would do the same).
-Check your seasoning on the now thick and cheesy sauce and add back in your veggies and chicken. Stir well and pour into a greased 9*13in baking dish and top with salted, buttered bread crumbs and parmesan cheese. Bake at 350* for 30-45 min, or until it bubbles along the sides of the dish and the top is nicely browned.