Preheat oven to 400°F. In a large bowl, toss the butternut squash with 1 tablespoon oil, sage, 1 teaspoon salt and 1/4 teaspoon pepper, until coated. Place on a parchment-paper-lined baking sheet, and bake until tender, about 25-30 minutes. 15 minutes before butternut squash is finished cooking, add kale in a single layer around butternut squash. Continue to bake until kale is wilted. Set aside.
In a large skillet, heat oil over medium-low heat. Add onions, and cook, stirring occasionally, until golden-brown, about 20-25 minutes. Season with remaining salt and pepper.
Slice Tribeca Oven Multigrain Loaf widthwise in 8 1/2-inch-thick slices. Spread the cranberry sauce evenly over 4 slices of bread. Top bottom half of bread with an even layer of the butternut squash, onions, pears, kale and Gruyere cheese, and then the remaining bread slices.
In a large skillet or griddle, melt butter over medium heat. Working in batches if necessary, toast sandwiches until light golden-brown, about 2-3 minutes per side. Repeat with remaining sandwiches and butter. Slice and serve.