Heat 1 Tbsp. (15 mL) oil in large nonstick skillet over medium heat and cook onions, stirring occasionally, 5 minutes. Stir in spinach and garlic and cook until onion is softened and mixture is dry, about 3 minutes.
Combine lentils, farro, Hellmann's® Vegan, bread crumbs, sun-dried tomatoes and flax seed in large bowl.
Stir spinach mixture into bowl and form into 6 patties. Heat remaining 1 Tbsp. (15 mL) in large nonstick skillet and cook patties over medium heat 10 minutes, turning once, until lightly golden and heated through.
Serve on buns with, if desired, lettuce and a dollop of Hellmann's® Vegan. Serve with lemon wedges if desired.