On a non-stick or parchment paper-lined baking sheet, combine the squash, garlic, oil and 1 bunch of sage. Season with salt and pepper. Roast for 30 minutes or until the squash is tender and golden, stirring halfway through. Squeeze the garlic cloves to separate the flesh from the peel, then mash the flesh into a paste. Compost the garlic peel and the sage. Set the squash and the garlic paste aside and keep warm.