Place basil in a food processor fitted with a metal blade; chop fine. Steam chunks over boiling water for about 5 minutes, or until just tender when pierced with a sharp knife.

Cut zucchini into l-inch chunks (you should have about 2 cups). Rinse and drain. Cook pasta according to package directions until tender.

Place them on a vegetable steamer over boiling water; cover and steam for about 25 minutes, or until tender when pierced with a fork. Leave whole or cut into large chunks. Scrub yams and cut out any rough spots. The easiest w,ay to cook a quantity of yams is to steam them. In a large bowl mash the flesh, then mix in all the pineapple, with its juice; Keep a few cooked yams on hand for a tasty, nutritious snack or addition to a meal. Peel cooked yams when they are cool enough to handle. Fill each of the cavities with remaining pineapple. To make the sauce: In a large saucepan, combine beet, celery, carrot, onion (if used), dill, and 2 cups of the water. Chop enough of the remaining cabbage to make 1 cup. When cabbage is cool enough to handle, carefully remove 8 large outside leaves and set aside.

Remove cabbage from the pot. In a large covered pot steam cabbage for about 20 minutes, or until quite soft when pierced with a fork. Remove any wilted cabbage leaves; cut out the core with a sharp knife. Combine with pasta and toss to mix. Process in short on-off bursts until everything is chopped fine. Add zucchini, salt, garlic, and tahini (if used).