1. Prepare rolls. Cut bell pepper into thin strips. Halve green onions lengthwise, then cut into thirds. Cut snow peas into thin strips, discarding strings. Cut cucumber into thirds, then cut into thin strips. Trim lettuce head; cut leaves into 2-inch square pieces. Remove mint, basil, and cilantro leaves from stems (½ cup each).
2. Fill large sauté pan halfway with water; bring to gentle simmer on medium-low. Remove pan from heat; dip 1 rice paper wrapper carefully and quickly into warm water, then place on flat work surface. Place 1 piece lettuce down first, top with small amount each carrots, bell peppers, green onions, snow peas, cucumbers, mint, basil, and cilantro.
3. Roll end of rice paper wrapper over filling, fold in the ends and roll into a tight cylinder. Repeat with remaining wrappers and fillings. Store rolling in-between layers of damp paper towels to help prevent the wrappers from sticking together.
4. Prepare sauce. Juice limes (about 1 cup). Place in medium bowl: lime juice, fish sauce, sugar, chili-garlic sauce, and garlic paste; whisk to blend. Serve rolls with dipping sauce.

Chef's Tip: Try adding about 2 tablespoons leftover cooked shrimp or chicken when assembling each summer roll.