Prepare Grilled Jalapeño Dressing and Corn: Prepare outdoor grill for direct grilling over medium heat. Place jalapeño and corn on hot grill rack; cook jalapeño, covered, 8 minutes or until tender and charred in spots, turning occasionally; cook corn, covered, 10 minutes or until golden brown, turning frequently.
Transfer jalapeño to small bowl; cover with plastic wrap and let stand 10 minutes. Remove as much charred skin from jalapeño as possible. Cut off and discard stem end of jalapeño; cut lengthwise in half. With paring knife, scrape out and discard seeds. Let corn cool; cut corn from cob.
In food processor with knife blade attached or blender, purée garlic, sour cream, oil, lime juice, salt, black pepper and jalapeño until well blended. Makes about ⅔ cup.
Prepare Cobb Salad: On large serving plate, place romaine; arrange rows of corn and remaining Cobb Salad ingredients over romaine in order listed. Serve with Creamy Grilled Jalapeño Dressing.