Grate the carrots and zucchini, and place them in a large bowl. Add the diced walnuts and onion, and stir to combine.
In a medium bowl, whisk together the eggs, flour, and salt. Add the egg mixture to the vegetable mixture and stir.
Heat the avocado oil in a large skillet over medium heat. Form the carrot zucchini mixture into patties using about 3 tablespoons of batter for each pattie. Cook for about 3 minutes on each side. Repeat until all the fritters are made. (Yield: 12 fritters)