Dice the three carrots and white onion.
Melt the olive oil over medium heat in a large pot (I use a stew pot). Add the onion and carrot and saute until onion is translucent.
Add the ground beef and brown, breaking up any clumps. Add about ¼ tsp pepper and ½ teaspoon salt.
Once beef has browned reduce heat to low and add the milk to the pot and stir occasionally until all the milk is absorbed.
Sir in the nutmeg and oregano.
Take the can of tomatoes and put into a blender. Blend until smooth. Add the tomatoes to the pot and stir to mix.
Bring the sauce to a boil, then reduce the heat to low and simmer uncovered for 1-1.5 hours, stirring occasionally. Add salt and pepper to taste.
While sauce is cooking, preheat the oven to 425 degrees F.
Cut the spaghetti squash in half and scoop out the seeds. Place face up on a foil-lined baking sheet. Drizzle one tablespoon olive oil over the squash halves and rub into the surface. Season lightly with salt and pepper. Flip over so squash is face down on the baking sheet. Bake in oven for 45 minutes.
When squash is done, remove from the oven and flip over. With a fork, fluff the squash to form strands. Scoop strands into bowls and spoon the bolognese sauce over the spaghetti squash.
Top with fresh basil leaves if desired.