Tricolor Potatoes with Pesto and Parmesan

INGREDIENTS

• 1 1/2 pounds red-skinned new potatoes
• 2 large shallots
• 8 tablespoons olive oil
• 3/4 cup freshly grated Parmesan cheese
• 1 cup (packed) fresh basil leaves
• 1 1/2 pounds Yukon Gold potatoes (each about 1 1/2 inches in diameter)
• 1 pound purple potatoes (each about 1 1/2 inches in diameter)
• Nonstick vegetable oil spray
• 4 garlic cloves