Mix the spinach puree with the dosa batter and fill in the squeezer bottle through a funnel.
Pour few drops of oil on a hot tawa / griddle and sprinkle some water. After the water sizzles off, rub with a half cut onion.
Reduce the flame and gently squeeze the bottle on the tawa to make a webbed pattern. Drizzle some oil around the edges and cook for 2-3 minutes till it is done on one side.
Gently flip it over and cook the other side too. Remove on a plate carefully. Make similar webbed Dosas with the remaining batter.
Each time you make a dosa, rub the hot tawa with the cut onion. This ensures a non-stick coating and easy removal of the dosas. Serve them hot with chutney and sambar.