To prepare pancakes, place potatoes, zucchini, and onion in a clean kitchen towel, and squeeze out excess liquid. Combine potato mixture, egg substitute, matzo meal, 1/4 teaspoon salt, and dash of pepper in a large bowl, and stir gently to blend.
Heat 1 teaspoon canola oil in a nonstick griddle or large nonstick skillet over medium heat. Spoon about 1 cup potato mixture onto hot pan, spreading to a 6-inch diameter. Cook 3 minutes on each side or until lightly browned and cooked through. Transfer to a plate; keep warm. Repeat procedure with the remaining 3 teaspoons oil and remaining potato mixture.
To prepare salad, combine tomatoes and remaining ingredients in a medium bowl; toss gently. Serve salad on top of pancakes.