Place zucchini or carrots in a steamer basket and steam over boiling water until very tender (about 8 minutes for zucchini and about 15 minutes for carrots). Drain; mash with a potato masher.
Beat egg in a medium bowl; stir in mashed zucchini or carrots, matzo meal, salt, and pepper.
Heat a lightly oiled skillet or griddle over medium heat. Add the vegetable mixture, a rounded tablespoon at a time, spreading each mound into a 2 1/2-inch circle. Cook about 4 minutes or until golden, turning once.
Keep cooked latkes warm in the oven while frying the next batch. Makes 10 latkes, 5 side-dish servings. Nutrition information is given per serving (2 latkes each).