Start with 2 3-ish pound spaghetti squashes. Cut in half, cut ends off, and scoop out the seeds inside. Lightly coat inside with olive oil, salt, and pepper.
Place squash halves inside-down on a cookie sheet and bake at 400 degrees for 30 minutes.
While squash bakes, melt 2 tbsp of butter in a cast-iron skillet over medium heat.
Salt and pepper each side of 2 separate 1lb sirloin steaks and grill in the skillet for about 5 minutes per side (or to your preference). This will produce a steak that's cooked medium.
Remove the steak and allow it to rest for 10-15 minutes. Lower heat to low and scrape out and remove any burnt pieces from the bottom of your pan with a wooden spoon, leaving remaining cooking liquids.
Into the cooking liquids, add a jar of Bertolli® Organic Traditional Tomato & Basil Sauce and a jar of Bertolli® Organic Creamy Alfredo Sauce; stir well.
Once the spaghetti squash is finished cooking, allow to cool for 15-20 minutes. Then, use a fork to shred! Place your shredded squash in a large bowl, leaving 1/2" of squash around the peel to give the stuffed squash a little bit of stability.
Once steak has rested, slice against the grain into bite-sized pieces. Add into shredded squash, along with the Rosa sauce.
Once shredded squash, steak, and sauce is mixed together, spoon mixture back into the squash shells.
Top the 4 stuffed squash halves with 1 cup shredded mozzarella cheese and 1 cup shredded parmesan cheese. Bake at 350 degrees for 10 minutes, until cheese on top is melted and slightly brown.