In a small saucepan, combine boiling water and couscous. Remove from heat; cover and let stand for 5 minutes.

Meanwhile, in a small saucepan, cook mushrooms, corn (if you like), snipped chives, snipped tarragon, and snipped basil in 1 tablespoon herb oil for 3 minutes or until mushrooms are tender. Remove from heat; set aside.

If you like, peel tomatoes. Cut a 3/4-inch slice off the top of each tomato, reserving slices for lids. Scoop out the seeds and the center flesh. Chop enough of the center to make 1 tablespoon; set aside. Discard remaining pulp.

Brush insides of tomato with a little herb oil. Place tomatoes, cut sides up, in a 13x9x2-inch ( 3-quart rectangular) baking dish. Place a clove of garlic, sprig of thyme, sprig of tarragon, bay leaf, and basil leaf into each tomato. Put the tomato lids on and roast in a 325 degree F oven for 10 to 12 minutes or just until tomatoes begin to soften. Remove and discard the garlic and herbs. Set tomatoes aside.

Drain liquid from couscous. Stir in mushroom mixture, reserved chopped tomato, pine nuts and cucumber (if you like) until thoroughly combined. Stir in 1 tablespoon herb oil. Season to taste with salt and pepper. Spoon into tomatoes; top with lids. Brush tomatoes with additional herb oil. Return to oven for 5 minutes.

Place one tomato on each plate. Garnish each with two chive pieces. Makes 8 servings.