Cheesy Broccoli and Rice Gratin

Please pardon the horrific picture. This simple yet delicious gratin (read: casserole) was made in the midst of a week of relentless rain, fog and eventually snow in which the sun didn't show it's face and all pictures I took came out looking like the one below. But because of said weather I felt the need to make lots of filling comfort food and let's face it, I was stuck indoors so there wasn't much else to do but cook-and this cheesy dish fit just the bill. It's like mac and cheese but healthier, and with broccoli -o.k, maybe it's not like mac and cheese at all but I kind of felt like I was eating mac and cheese even though it was with brown rice and lots of broccoli so I felt better scarfing it down.  I think my husband was a little nervous when I told him what I was making  and I could see his mind working on thinking of all the contents of the fridge he could fall back on if this turned into a disaster BUT he was in for a surprise because it was so. darn. good. I used brown rice because we are supposedly on a "diet" but feel free to use white rice and I used a combo of cheddar, yellow cheese and Parmesan cheese but feel free to use other cheeses if you have them such as Gruyere of Mozzarella. Enjoy!

3 cups cooked brown rice
1 head broccoli, broken into florets
4 Tbl butter
3 cloves garlic, minced
4 Tbl flour
2 cups whole milk
1 1/2 tsp Dijon mustard
1 cup yellow cheese, shredded
1 cup cheddar cheese, shredded
1 cup Parmesan cheese, shredded
salt and pepper to taste

Preheat oven to 350. Blanch the broccoli florets in boiling salted water for 2 minutes and then drain. In a sauce pan heat the butter and saute the garlic cloves for about 2 minutes. Add the flour and whisk  constantly for about 3 minutes (the mixture will get thick) Slowly add the milk and mustard, season with salt and pepper and keep mixing until the mixture is thick, like a cheese sauce. Remove from heat and mix in all the cheeses reserving 1/4 cup of each cheese for the top.  Mix the rice, broccoli and cheese sauce together and pour into a greased pan. Top with the remaining cheeses and bake for 35 minutes until the top is golden.