1. Cut the acorn squash in half and remove the seeds.

2. Place the squash in a baking dish and drizzle with some olive oil. Season with salt and pepper.

3. Bake in a preheated oven at 200 degrees Celsius for about 30 minutes, until the squash is tender.

4. Meanwhile, prepare the filling. Heat the anchovy paste with the 1% milk in a pan.

5. Dissolve the arrowroot in some water and add it to the milk mixture. Stir well until the sauce thickens.

6. Grate the Asiago cheese and add it to the sauce. Continue stirring until the cheese melts and the sauce is creamy.

7. Remove the baked squash from the oven and fill it with the sauce.

8. Return to the oven and bake for another 10 minutes, until the sauce is golden brown.

9. Garnish with fresh basil and serve.