Cut zucchini in half lengthwise. Place, cut side down, in a microwave-safe 2-quart square baking dish. Micro-cook, covered, on 100 percent power (high) for 1-1/2 to 3 minutes or until nearly tender. (Or, cook in boiling water for 3 to 4 minutes.) Scoop out pulp, leaving a 1/4-inch-thick shell. Set shells aside. Finely chop the zucchini pulp; set aside.

In a medium saucepan cook onion in hot oil until tender but not brown. Add chopped zucchini; cook 1 minute more. Stir in flour, basil, and pepper. Add milk all at once. Cook and stir until thickened and bubbly. Cook and stir for 1 minute more. Gradually add zucchini mixture to the egg product or egg. Stir in Parmesan cheese. Spoon mixture into zucchini shells; place in a 2-quart baking dish.

Bake, uncovered, in a 350 degree F. oven for 25 to 30 minutes or until filling is lightly browned. Makes 4 side-dish servings.

Prepare and fill zucchini; cover and chill up to 24 hours. Bake as above except bake 30 to 35 minutes.