Pre-heat the oven at 375*.
Cut one spaghetti squash in half from stem to bottom (length-wise).
Scrape out the seeds and pulp.
Season however you like, I drizzle mine with olive oil and sprinkle garlic salt on it.
Place each half of the squash face down (skin side up) and bake for 30 minutes.
While the squash is baking, combine the tomato sauce, tuna, capers, garlic powder, onion powder, and lemon zest in a heavy large skillet.
Using a fork, break the tuna into chunks. Simmer to blend the flavors, about 5 minutes. Season with salt and pepper, to taste.
Remove from the oven and let cool a bit.
Use a fork to pull the strands out of the squash onto a plate.
Serve sauce over the squash and enjoy!