Preheat oven to 400˚F (I use convection roast but regular bake works fine too)
Line a cookie sheet with tin foil; place the squash cut-side down on one side of the sheet. In a large bowl, toss the cut tomatoes with the oil, vinegar, salt and pepper; place cut side up on sheet next to squash.
1 spaghetti squash, 10 tomato, 1 tbsp olive oil, 1-2 tsp balsamic vinegar, ½ tsp salt, 1 pinch pepper
Roast for about 40 minutes OR until the squash is fork tender. It can take as little as 30 minutes or as much as one hour, just check it.
When squash is cooked, remove sheet (with the tomatoes) from the oven, allow to cool until you can handle the squash. Carefully scoop squash from shell. You want to do this in the same direction as the fibres so that the spaghetti-like fibres remain intact. I use a fork for this. Place the squash in an ovenproof platter, spread it out and try to separate the fibres so that it looks like spaghetti noodles.
Chop the tomatoes in about six pieces each; scatter on top and a little throughout the squash. Generously season with pepper.
Place back in a 350˚F oven and cook for about 30 minutes or even up to one hour. This will dry out the squash and meld all the flavors – you can skip this part if you want, but I like it double cooked. It also makes it a great dish to entertain with because you can put it in a low oven (300˚F) and forget about it for a long while.