- Blend garlic, rosemary, pepper and salt in food processor until garlic and rosemary are finely chopped. Gradually blend in oil. Combine squash, potatoes, shallots and turnip in large bowl. Add 1/3 cup rosemary-garlic marinade and toss to coat. Combine green and red bell peppers and eggplant in large bowl. Add 1/3 cup marinade and stir to coat. Let vegetables stand 30 minutes, tossing often. Reserve remaining marinade.
- Position 1 rack in top third and 1 rack in bottom third of oven and preheat to 375º F.
- Spray 2 large baking sheets generously with nonstick spray. Arrange squash, potatoes, shallots and turnip in single layer on 1 sheet; place on upper rack in oven. Arrange green and red bell peppers and eggplant on second sheet. Place on lower rack in oven. Roast all vegetables 30 minutes.
- If vegetables on sheet with eggplant are tender, remove sheet to work surface, or roast on upper rack 5 to 10 minutes longer. Stir potato mixture on second sheet. Roast on bottom rack until tender and brown, about 15 minutes longer.
- DO-AHEAD TIP: Can be made 2 hours ahead. Let stand on sheets. Rewarm 20 minutes in 375°F oven.
- Arrange vegetables on platter. Drizzle with some of reserved marinade. Serve, with remaining marinade.