In a large skillet over medium heat, soften the onion in the oil. Add the garlic, ginger, thyme, curry powder and red pepper flakes. Cook for 1 minute. Add the chickpeas, potatoes and water. Bring to a boil and simmer for 20 minutes or until the potatoes are tender. Add the peas and green onion. Let simmer for 2 minutes, mashing a few potato pieces with a fork to thicken the curry. Season with salt and pepper. Keep warm.
Split Pea Purée
Meanwhile, in a small pot over medium heat, soften the onion in the oil. Add the spices and split peas. Cook for 1 minute, stirring to coat the peas. Add the water and season with salt. Bring to a boil and simmer for 20 minutes or until the peas are cooked but still firm and have absorbed all of the water.
In a food processor, pulse the split pea mixture until the peas are the size of bread crumbs. Set aside.
In a bowl, combine the flours, baking powder and salt. Add the water and oil. Using a wooden spoon, mix until the dough forms a ball. On a lightly floured work surface, knead the dough for 1 or 2 minutes or until completely smooth. Wrap in plastic wrap and let rest for 10 minutes.
Divide the dough into 8 equal pieces. Shape each piece into a disc about 5 inches (13 cm) in diameter. Working one at a time, place 2 tbsp of the split pea purée in the centre of each disc. Bring the edges towards the centre until they meet, then pinch them closed. Repeat with the remaining dough. Wrap each disc in plastic wrap or cover with a towel to keep the dough from drying out.
On a lightly floured work surface, roll out each disc to a circle 10 inches (25 cm) in diameter.
Brush a large non-stick skillet with butter and place the skillet over medium-high heat. Cook one roti at a time for about 1 minute per side. Transfer to a plate and cover with a towel to keep warm.
Spread 1 cup (250 ml) of chickpea curry in the centre of each roti. Close by folding the sides in towards each other and turn so the folds are underneath. Delicious served with tamarind sauce (see recipe) and hot sauce.