Peel onion and chop fine. Peel and grate carrots. Peel and grate zucchini. In a skillet, sauté onion in butter until soft. Add carrots and zucchini. Sauté until soft. Sprinkle with flour. Stir to combine. Add garlic, dill or parsley, lemon juice, cottage cheese, cream cheese and Parmesan cheese. Add eggs. Season to taste. Pour mixture into a large, lightly greased pan. Smooth top. Bake at 375° for about 1 hour, or until mixture is set and lightly brown on top. Let sit for a couple of minutes before serving.