Afghani Squash Casserole

Ingredients

• winter Squash

  peeled and cut into 2 1/2-inch cubes
  2 lb
• spaghetti sauce
  4 cups
• ground cinnamon
  2 tsp
• ground cloves
  1/4 tsp
• freshly ground black pepper
  1 tsp
• plain yogurt
  1 1/2 cups
• Tbs. minced fresh mint

  or 1 tsp. dried, plus extra for garnish
  1 unit
• minced scallions
  1/4 cup
• salt
  1 tsp