Squash-Topped Cottage Pie

I know what you're thinking. "Squash-Topped? Are you serious? Is that supposed to entice me?" Two responses:
1. I know, it sounds weird, but it's delicious. Even the husband thinks so, and that's saying something! I think it actually tastes a lot more like sweet potatoes than squash. Try it and see!
2. Don't worry. There's cheese involved.

Squash-Topped Cottage Pie
Adapted from an Eating Well recipe by Beth Turner

1 lb. ground round
1/2 c. chopped onion
1 tbsp. tomato paste
2 tbsp. flour
1 c. beef broth
6 oz. (or about 6 c.) fresh spinach, chopped
dash of salt
dash of garlic powder
2 12-oz. packages of frozen winter squash puree, thawed
1/3 c. parmesan cheese, shredded or grated

Position top rack in upper third of oven and preheat broiler. In a large skillet saute the onion and beef until the onion is tender, add tomato paste and flour. Continue to stir until beef is browned. Add beef broth, stirring to scrape up tiny bits. Bring to a boil and cook until the broth is the consistency of gravy. Stir in spinach and about 1/4 tsp. of salt and garlic powder. After you stir in the spinach and remove from heat. Pour into a greased 9" x 13" dish.
Place squash in a sieve and press on it to extract liquid (you can squeeze it in a dish towel if you need to). Top meat mixture with pureed winter squash. Broil for about 10 min. or less, sprinkle with cheese and broil until cheese is melted and slightly browned. (about 3 min). Serves 6.

Tips:
-I forgot the tomato paste and lived to tell about it.
-I'm becoming more and more inclined to never use garlic salt or garlic powder and always use fresh minced garlic. I can never add the right amount of the dried stuff, so I like to go with the fresh. If you prefer that, just add the fresh stuff when you cook the beef and onion.
-1 beef bouillon cube + 1 c. water = 1 c. beef broth... I'm just throwing that out there. Worked for me.
-If you're up for a some extra work (or if your grocer doesn't stock winter squash puree), you can buy a winter squash whole, cut it in half, scrape out seeds, place cut-side-down on a foil-covered jelly-roll pan and bake at 350 for 45-60 min. Let cool for a couple of minutes, then scrape out the squash and puree in a food processor. If you don't have a food processor, I bet you could just blend it with a mixer for a few minutes and achieve a puree-like consistency (after baking for so long, it's very tender). It sounds complicated, but the worst part is really babysitting the thing for 45-60 min. The rest is NOT hard at all. The squash scrapes out very easily. Ohh, and break out the big-daddy knife to cut that sucker in half. They're dense!

Here's a shot of the side of my casserole dish. The cheese is the white/brown, the squash puree is yellow, and you can barely see the spinach/meat mixture poking through on the side. So warm. So bubbly. So good.

Also, in case you didn't know. This is a winter squash. Is it the same as an acorn squash? I mean, it kind of looks like a giant acorn?