Cook pasta in salted boiling water until al dente. Drain and set aside.
Mix flaxseed and water to form flax egg. Let rest 5 minutes.
In blender, pulse lentils, breadcrumbs, onion, garlic, soy sauce, oregano, basil, chili flakes, salt, and pepper until combined.
Stir in flax egg, shape mixture into small balls.
Bake meatballs on a tray at 375°F for 20 minutes until firm and golden.
Heat olive oil in skillet, add marinara sauce, nutritional yeast, and lemon juice. Simmer 5 minutes.
Toss meatballs into sauce, coat gently.
Add pasta, mix, garnish with parsley, and serve hot.