Make Ahead Tip: Cover and refrigerate the chipotle mayonnaise (Step 3) for up to 5 days.
Ingredient Note: Chipotle chiles in adobo sauce are smoked jalapeños packed in a flavorful sauce. Look for the small cans with the Mexican foods in large supermarkets. Once opened, they'll keep up to 2 weeks in the refrigerator or 6 months in the freezer. You can also find them dried with other chiles or at melissas.com and ground in the spice section of many supermarkets.
To oven-roast peppers:
1. Preheat oven to 450°F. Place a wire rack on a large baking sheet. Arrange whole bell peppers on the rack.
2. Roast peppers in the center of the oven, turning occasionally with tongs, until blackened in places, 30 to 40 minutes.
3. Transfer the peppers to a large bowl and cover with plastic wrap. Let steam for 10 minutes. Uncover and let cool.
4. With a paring knife, remove stems, skins and seeds. If serving as antipasto, combine accumulated juices with peppers.
To oil the grill rack: Oil a folded paper towel, hold it with tongs and rub it over the rack. (Do not use cooking spray on a hot grill.) When grilling delicate foods like tofu and fish, it is helpful to spray the food with cooking spray.