Smoky Black Bean Burgers on Potato Buns

Name: Smoky Black Bean Burgers on Potato Buns
Ingredients: For the Burger Patties & Mayonnaise; 1 tablespoon flaxseed meal; 2,5 tablespoons water; 250 grams cooked black beans; 30 grams almond meal; 1 tablespoon cilantro; 1 tablespoon parsley; 7 grams garlic, minced; 30 grams red onion, minced; 0.5 teaspoons paprika powder; 1 teaspoon cumin powder; 1/2 teaspoon salt; 1/2 teaspoon black pepper; 125 milliliters sunflower oil; 1 teaspoon cider vinegar; 1/4 teaspoon salt; 1 tablespoon dijon mustard; 8 grams flax seed meal; 30 milliliters water; For the Potato Buns & Burger Fillings; 400 grams mashed potatoes; 44 grams gluten-free flour; 1 tablespoon mustard; 1 piece Non-stick cooking spray; 30 grams romaine lettuce; 120 grams tomatoes