Combine lemon peel, lemon juice, mustard, sugar, salt, and garlic in a screw-top jar. Cover and shake well. Chill for 2 to 24 hours.
Cook tortellini in a large saucepan according to package directions, adding asparagus to pan for the last minute of cooking time; drain. Rinse tortellini and asparagus with cold water; drain again.
Toss tortellini-asparagus mixture with olive oil in a very large bowl or container. Cover and chill for 2 to 24 hours. Seal chopped sweet pepper, cheese, green onion, nuts, and sweet pepper halves in separate self-sealing plastic bags.
Transport all ingredients in an insulated cooler with ice packs. To serve, stir chopped pepper, cheese, green onion, and nuts into tortellini-asparagus mixture. Shake dressing; pour over all, tossing lightly to coat. Spoon mixture into sweet pepper halves. Makes 10 side-dish servings.