Using a sharp knife cut the squash in half from stem to bottom. (If too hard to cut, microwave for 3-5 minutes to soften first.) Scoop out seeds and discard (or see note for using the seeds). Place the two halves face down in a casserole dish or on a rimmed baking sheet. Reserve one of the shell halves to serve in, if desired.
Bake at 400° for 50-60 minutes (this will depend on the size of the squash). When done, the outer skin will be soft enough for a fork to easily penetrate.
Prep the remaining ingredients, as the rest of the dish will come together quickly.
Once the squash is tender, remove from the oven and set aside to cool enough to handle, turn squash face up and use a fork to separate the strands. Set aside until ready to toss with the other ingredients.
Heat 2 tablespoons of olive oil in a skillet over med-low heat, add garlic, and cook 2-3 minutes until fragrant. Add spaghetti squash to the skillet and stir to incorporate the garlic and warm the squash.
Add tomato, basil, and feta; toss to combine. Remove from heat and drizzle with an additional 2 tablespoons of olive oil. Serve immediately or cover until ready to serve.
Spaghetti squash is resilient. If stored in a cool, dry place at 60ish degrees, it will keep for up to 3 months.
Prep ahead by roasting and storing in the fridge for up to 10 days. To save even more time, roast more than one squash at a time–freeze in 1 cup measurements.
Easily reheat leftovers by spreading in a casserole pan, top with additional cheese and heat for 10 minutes in a 350°F oven until warmed through and cheese is melted.
Clean and roast the seeds with a little olive oil and salt for snacking.
Squash size affects the ratio of ingredients; use this recipe as a guide and adjust as desired.
Substitute any kind of cheese, just be sure to adjust for salt. Feta brings a salty, briny flavor, so if adding a mild cheese you may want to add a little more salt.
Substitute canned tomatoes for fresh tomatoes, especially in the winter if quality, flavorful tomatoes are hard to find.