Make the corn patties:
Place all the ingredients in a food processor and process just until you have a mixture that holds together when you pick up a piece and form a ball. Don't overprocess because you don't want a paste-- you should still have some texture from the corn and the scallions.
Divide the dough into 10 balls and then flatten each into a pattie, about 2 inches in diameter (if, for any reason, you find the mixture is too runny, add some cornflour so it holds together. My measurements worked perfectly for me.)
Smear or spray some oil over a cast-iron or non-stick skillet. Heat. Place as many patties as you can without crowding the skillet, and cook on each side until quite brown and crusty.
Make the tomato sauce:
Heat the oil in a skillet.
Add the spring onions and saute until they start to brown.
Add the tomato puree and ketchup and cook until the mixture starts to turn darker.
Add chilli powder and salt to taste. Turn off heat.
Serve with the Makai Patties.