Pierce squash all over with the tip of sharp knife. Put in a microwave-safe dish and microwave 15 minutes on high, or until slightly soft. Let cool 10 minutes or until cool enough to handle, then cut in half crosswise, scoop out and discard seeds. Flesh will be in long spaghetti-like strands.
Scoop squash into large bowl and season with butter, parsley, oregano, salt, pepper and red pepper flakes. This stage alone yields a delicious side dish.
While squash cooks and cools, make your sausage and peppers.
Slice red bell pepper and red onion into lengthwise strips. You may need to cut the pepper strips in half to be fork-size.
Heat 1 T olive oil in a large non-stick pan over med-high heat. Squeeze sausage out of casings in little meat balls and fry until browned and cooked through. You may need to do this in two batches depending on the size of your pan. Remove sausage and set aside to keep warm.
Toss peppers and onions into pan. Cook until softened. You may need to add a bit more oil, or a few tablespoons of wine to deglaze the pan. When vegetables are about 2 minutes away from being done, add minced garlic to pan and heat till fragrant. Then return sausage to pan and add several handfuls of spinach. Toss to coat spinach until just wilted and sausage is reheated.
Serve immediately over prepared squash. If you can tolerate dairy, I'm sure fresh parmesan would be great, but it was already delicious without it.