Press the tofu for 20 minutes to remove excess moisture.
Grate the pressed tofu using the large holes of a box grater and set aside.
Heat the olive oil in a wide skillet over medium-high heat. After 90 seconds, when the oil is hot, add the grated tofu. Cook, stirring occasionally for 7-8 minutes until evenly lightly browned and crisp all around.
Add the diced onion and garlic and continue to sauté over medium-high heat for 3-4 minutes until softened.
Stir in the diced tomato, chopped parsley, water, tomato paste, tamari, oregano, paprika, crushed red pepper flakes, and nutritional yeast. Cook over medium heat, stirring frequently, until the liquid is absorbed and the mixture somewhat resembles ground meat. Remove from heat and allow the mixture to cool fully.
Once cooled, transfer the mixture to a bowl and add flour until a firm, workable dough forms.
Shape into evenly sized balls (about 4 teaspoons in size), pressing firmly so they hold together.
Heat the olive oil in a clean skillet over medium heat. After 90 seconds, when the oil is hot, add the meatballs in a single layer. Cook, turning regularly, until browned and crisp on all sides.
Warm the marinara sauce in a separate pan over medium heat until heated through. Transfer the meatballs to the sauce and simmer briefly to coat. Serve the meatballs warm, ideally over pasta garnished with chopped parsley, or in a sub.