Whisk together the flour and water in a mixing bowl until smooth and free of lumps. Add 3 tablespoons of the oil, the thyme, parsley, salt, and pepper and whisk until the mixture is the consistency of pancake batter. Cover and let the batter stand for at least 1 hour at room temperature, or up to 2 hours if you have the time.

When ready to bake the farinata, preheat the oven to 425°F.

Whisk the batter again to bring it back together. Put a 10-inch cast-iron or other heavy ovenproof skillet over medium heat and add the butter substitute and the remaining 2 tablespoons oil, swirling the pan to coat. When all the butter substitute has melted, add the squash and shallot and cook, stirring, until soft, about 4 minutes. Season with salt and pepper.

Spread the squash and shallot evenly in the skillet and pour the batter over it. Carefully transfer to the hot oven and bake for 30 minutes, or until the farinata is no longer wet in the center and the edges are browned and pulling away from the sides of the pan. Remove the farinata from the oven and cool in the pan for 10 minutes.