Combine all hamburger ingredients in a large bowl and mix well. A thorough kneading of the mixture will produce firm, solid hamburgers that don’t fall apart when broiling. With wet hands, form flat, round two-inch hamburgers.

Lay the hamburgers in a baking pan, cover with plastic wrap and refrigerate for two hours. When preparing a large amount, store the patties in several layers separated by Gefen Parchment Paper.

For authentic hamburgers, broil the patties on a barbecue or electric grill. Alternately, bake the patties in the oven for 12 minutes or fry for three minutes on each side in a frying pan using a small amount of oil.

In a food processor, grate horseradish using the fine grater disc. Remove the grater disc from the food processor and add the metal blade, leaving the grated horseradish inside. Mince the horseradish until smooth and creamy.

Add almond flour, water, vinegar, sugar, and salt and blend until smooth.

Add light mayonnaise, mix with a spoon and season to taste.

Break a matzo into quarters. Top each quarter with a small lettuce leaf, a teaspoon of horseradish sauce, and a hamburger. Serve on a large tray.