Preheat the oven to 425 degrees.
Slice the butternut squash about ⅛-inch thick (I used a mandoline). Set aside.
The top part
In a large skillet over medium-high heat, brown the ground beef with the onion.
1 pound ground beef, 1 sweet onion
While it’s cooking, puree the can of chipotle peppers until smooth.
1 7- oz can of chipotle peppers in adobo sauce
Add the pureed peppers to the beef once it’s browned.
1 7- oz can of chipotle peppers in adobo sauce
Stir it in until well combined and lower the heat to a simmer.
Spray a casserole dish (mine is 11×8 I think) and put down a layer of sliced butternut.
Top the butternut with ⅓ of the chipotle beef mixture and 1 ounce of the cheese.
3 oz Colby-Jack cheese
Top with another layer of butternut, beef, and cheese.
Make one more layer, this time just the butternut and beef. Set aside the last ounce of cheese.
Cover with aluminum foil and bake for about 25 minutes.
After 25 minutes, remove the aluminum foil. Test the doneness of the squash; it should be soft. There may be a lot of liquid that escaped from the butternut — simply remove as much as you can with a baster.
Top everything with the last ounce of cheese and bake for about 10 more minutes, so the cheese melts and just starts to brown.
Cut into 6 servings and enjoy!