Cauliflower Pasta

Ok, so I made this last night and got mixed reviews. The kids LOVED it and Jared added marinara sauce to it to make it better. I liked it, but thought the flavor was a bit subtle. When I had it again today for leftovers I thought it was great. Honestly, I'm not totally sure if mine turned out totally right, my cauliflower didn't mash enough to make a sauce, but I kind of liked having the cauliflower be chunky. Anyway, if you like cauliflower, you should try this!

Ingredients
1 pound penne rigate
Salt
1/4 cup extra-virgin olive oil
3 cloves garlic, cracked from skin and sliced
1 red onion, finely chopped
1 head cauliflower, stem removed and chopped
1 cup vegeteable (or chicken) stock
4 sprigs fresh rosemary, leaves stripped and finely chopped (or 3/4 tsp. dried)
3/4 cup grated Romano, 3 generous handfuls
Salt and black pepper

Directions
Bring a large pot of water to a boil. Add salt and pasta and cook to al dente. Drain and reserve 2 ladles of pasta water.
While water is coming up to a boil and pasta cooks, make sauce. Heat a deep skillet over medium heat with extra-virgin olive oil. Add garlic and cook 3 minutes, then remove. Add onions and cook 5 minutes then add cauliflower, stock and the rosemary. Cover the pan and cook 15 minutes. Uncover the sauce, add 1 to 2 ladles of pasta water and mash the cauliflower with the back of a wooden spoon or potato masher. Add the pasta and cheese to the cauliflower and toss to combine. Season the dish with salt and pepper, to taste, and serve.