In a large skillet, heat the oil on medium heat.
Add the chopped green chili or red chili. Stir a couple of times and add the mustard seeds. Be careful as they splutter.
Give it less than 30 seconds, and add the curry leaves. Stir and add the onions.
Sauté the onions for about 6 minutes until they are translucent and start to turn reddish in the corners.
Add the tomatoes and sauté for another 4 minutes until the tomatoes are soft and the oil starts to surface.
Add your choice of nuts (optional) and give them a stir.
Now stir in the toasted bread cubes until they are nicely coated with the onion and tomato mixture.
Add a ¼ cup of water. Lower the heat and cover the skillet. Let it cook for 2-3 minutes.
Remove the lid, sprinkle the juice of half a lemon/lime, and stir. Cover and let it sit for 5 minutes before serving.
Remove to a serving dish and garnish with the chopped cilantro.