Heat oil in a large pot or Dutch oven over medium heat.
Add onions and sauté until softened and golden brown.
Add garlic, ginger, and green chilies and cook for a minute more.
Stir in turmeric, coriander, cumin, garam masala, chili powder, paprika, and curry powder. Cook for a minute, stirring constantly.
Add chicken pieces and cook until lightly browned.
Add prawns and cook for a few minutes until they turn pink.
Pour in chopped tomatoes and coconut milk. Bring to a simmer, then reduce heat and let it cook gently for 20-25 minutes, or until the chicken is cooked through and the sauce has thickened.
For the Roti
In a large bowl, combine flour, salt, and oil.
Gradually add water while kneading to form a smooth and pliable dough.
Cover the dough with a damp cloth and let it rest for at least 30 minutes.
Divide the dough into small balls.
On a lightly floured surface, roll each ball into a thin circle using a rolling pin.
Heat a tawa (griddle) or skillet over medium heat.
Cook each roti for a few seconds on each side, until slightly golden brown and puffy.