Place potato in a saucepan, and cover with water. Bring to a boil. Reduce heat; simmer 15 minutes. Add zucchini and leek, and cook 6 minutes or until tender. Drain. Return mixture to pan; mash with a potato masher. Cool slightly. Stir in cornstarch and next 4 ingredients (cornstarch through egg).
Divide potato mixture into 16 equal portions, shaping each into a 1/2-inch-thick patty. Dredge in matzo meal.
Heat 2 1/4 teaspoons oil in a large nonstick skillet over medium-high heat. Add 4 patties; cook 2 minutes on each side or until browned. Repeat procedure with remaining oil and patties.