Make a batter by mixing flour, onions, tomatoes, carom seeds, chili, ginger, coriander leaves, red chili powder and salt with enough water to make a thick batter.
Beat the batter well with a fork for 1 to 2 minutes. Taste the batter to check if the salt & spice are enough.
Heat a pan with oil.
When the pan is hot enough, dip each slice of the bread in the batter on one side. Place them on the hot griddle.
On a low to medium heat, toast until firm and bread comes off from the pan. Spoon the batter on the top side or the other side, just before flipping it. Do it carefully. Toast on the other side as well.
Repeat frying on both the sides on a low flame until the batter is completely cooked. The toast must turn golden.
Serve besan bread toast right away.