1. Cut each goat-cheese log into 13 equal pieces, and roll into 1 1/4-inch balls.

2. Place the green olives in one bowl and the Kalamata olives in another. Roll half of the goat-cheese balls in the green olives, pressing firmly to coat well. Roll the remaining balls in the Kalamata olives, pressing firmly to coat well.

3. Spread the parsley out on a clean work surface, and roll all the balls in the parsley. Transfer the truffles to a plate, and cover loosely with plastic. Refrigerate the truffles until ready to serve.

4. In a medium stockpot, bring 3 quarts salted water to a boil. Add the squash, and cook until fork tender, about 8 minutes. Drain squash in a colander, and set aside.

5. In a medium bowl, combine the balsamic vinegar, scallions, and mustard seeds. Season with salt and pepper. Slowly whisk in the olive oil. Set the dressing aside.

6. When ready to serve, transfer the squash to a large bowl, and season with salt and pepper. Add half of the dressing; toss to combine. Arrange the greens on a serving platter, and arrange the squash salad over the top; the heat of the squash will wilt some of the greens. Drizzle the remaining dressing over the entire salad. Garnish with the chilled goat-cheese truffles.