Freeze-Ahead Lasagna Primavera

INGREDIENTS

• 1/4 cup olive oil, plus more for foil
• 1/2 cup all-purpose flour
• 2 garlic cloves, minced
• 6 cups whole milk
• 2 packages (10 ounces each) frozen chopped spinach, thawed and squeezed dry
• 1 package (10 ounces) frozen peas
• 1/2 pound carrots (4 to 5), halved lengthwise and thinly sliced
• Coarse salt and ground pepper
• 1 container (15 ounces) part-skim ricotta (about 2 cups)
• 1 large egg
• 1 package (9 ounces) no-boil lasagna noodles (12 to 16 noodles)
• 1 pound part-skim mozzarella, shredded
• 1 cup grated Parmesan