In a medium skillet, heat one tablespoon olive oil and sweat the onions, leek, green onions and garlic. On medium setting stir until just translucent, about three to four minutes. Cool. Set aside.
If using frozen green chick peas, cook for two to three minutes in boiling water, drain and cool.
In a food processor, pulse the chick peas with cooked red lentils until smooth. Add the cooled onion mixture and pulse to blend. Transfer to a bowl.
In same food processor, chop the herbs or by hand. Add herbs to chickpea mixture. Add the grated sweet potato, flour, chia seeds, salt and pepper and lemon zest.
Mix well until blended. If mixture seems wet, add a bit more flour. Chill in fridge for 30 minutes for best texture.
Shape into six patties
Pan fry in remaining two tablespoons oil in a non-stick skillet medium heat for five minutes per side.
Meanwhile, for pumpkin seed butter, combine all ingredients in a small bowl and whisk gently until desired consistency is achieved.
Serve burgers in a pita half drizzled with pumpkin seed butter and favourite garnishes.