Spaghetti squash dishes usually disappoint me. A surprisingly watery vegetable, spaghetti squash releases lots of juice that dilutes its usual partner of tomato sauce. The result? Bland flavor and mushy texture that is very far from what I expect from a pasta dish.
Here is my solution: make a highly concentrated sauce based on tomato paste, with lots of garlic, wine and chunky eggplant and mushroom pieces. The squash is roasted, then put into a pan with more sauteed garlic, freshly ground pepper and lots of Parmesan cheese (like cacio e pepe!). The eggplant mushroom sauce is then layered over the Parmesan squash mixture, like you would add sauce to a base of polenta. The dilution problem is gone. With all the umami flavor from Parmesan, wine and mushrooms, the blandness is gone, too. There is really nothing to be done about the mushiness, I am afraid, but treating the vegetable like a very textured polenta makes the mushiness less of a liability.