In a medium bowl, whisk together the eggs and one quarter of the olive oil until very frothy, about 1 minute.
In a separate bowl, whisk together the almond flour, flaxseeds, and salt. Add the egg mixture and stir until it’s a thick, sticky batter. Cover with plastic wrap and refrigerate for 2 hours.
Bring a large saucepan filled with 3 inches of water to a boil. Add 1 tablespoon salt.
With clean, wet hands, roll the refrigerated dough into small balls, using about 2 generous tablespoonfuls to make balls 1½-inches in diameter. Gently lower each ball into the boiling water, one at a time, as you make them. Reduce the heat to low, and let gently simmer for 10 minutes.
Meanwhile, add the remaining olive oil to a large sauce pot over medium-high heat. Add the celery and a generous pinch of salt. Cook, stirring occasionally, until the celery is slightly softened, 2 to 3 minutes. Add the chicken broth and bring to a simmer. Add the parsley and dill. Season to taste with salt and pepper.
Using a slotted spoon, transfer the matzo balls to the pot of broth. Cover and let simmer over low heat for 10 minutes to bring flavors together. Serve.