Adjust oven rack to center position and heat oven to 350 degrees. Finely grind macadamias in a food processor or blender. Add 1 1/2 cups of the rice, 1/2 the tofu, soy sauce, fennel, sage, and smoked paprika; continue to process to a paste. Turn into a large bowl. Stir in onion, flaxseed and remaining rice and tofu; stir to combine. Let the mix rest for 10 minutes for liquid to absorb.
Divide mixture into 24 scant 1/4 cup portions; flatten each portion into 2-inch patties and place on a silpat- or parchment-lined large rimmed baking sheet. Bake until firm and golden brown, about 30 minutes. Alternatively, you can turn the mixture onto a large sheet of bees wax wrap and roll into an 18-inch log. Remove wrap and cut the log in half, then cut each half into 12 pieces for a total of 24 patties. (Can be cooled and refrigerated in a covered container up to a week or frozen for several months.)
The number of patties you cook will determine the size pan and amount of oil you’ll need. You can cook 7 to 10 patties in a 12-inch skillet, 4 to 6 patties in a 10-inch skillet, and 2 to 3 patties in a small skillet. For the large skillet use 2 tablespoons of oil. For the medium skillet use 1 tablespoon of oil, and for the small skillet figure 1 1/2 teaspoons of oil. You need a generous coating of oil in the pan for the patties to properly brown.
To fry the patties, heat oil over medium-high heat in the appropriate size pan. Add patties and cook until crisp and brown on side, 3 to 5 minutes. Reduce heat to medium, turn the patties over and continue to cook until crisp and brown on the second side, 3 to 5 minutes longer. Serve with ketchup and mustard or other sauces.