For the Ravioli Dough:
In a mixing bowl add the eggs and 1/4 cup of water and beat with a spoon. Once the yolk and white has mixed, add the salt and mix well.Make a well in the middle of the flour and pour 1/4 of the egg water mixture. Mix everything together with a spatula or your hands. Once the mixture is incorporated, add 1/4 more and continue to knead and add till all the mixture has been incorporated in the flour. Knead the dough well for 5-7 minutes till the dough becomes smooth to touch. Now add the olive oil and knead the dough again for 10 minutes. Kneading helps develop the gluten required for the pasta. After kneading, the dough will be soft to touch. At this stage wrap it tightly in muslin cloth and place it in the refrigerator.
For the Filling:
Wash and dry the baby spinach leaves. Chop them finely and set aside. Also, wash, dry and mince the mushroom. In a pan heat butter/ olive oil and add the garlic and saute till the raw flavor disappears. Next, add the onions and cook till they are light pink in color. Next add the spinach and mushrooms, seasoning, salt and pepper.Saute the mixture till it becomes dry and all the water has evaporated. Turn down the flame and add the cheese. Mix well. Set aside to cool.
To make the Ravioli:
Make small balls out of dough and roll it into thin sheets,cut roundels or squares as per your wish.Place mixtures of the filling on the sheet.Brush egg on the edges and seal with another roundel or square and press the edges with a fork. This gives the Ravioli a nice design and also seals the edges tight. Now place them in a plate dusted with flour. heat water in a deep pan. Add a pinch of salt to it. Next drop in 2-3 raviolis and let them simmer. The pasta will sink at first, and once cooked it becomes light and floats to the top. Also, it will become slightly transparent. That is the time to remove the ravioli and serve it with a sauce of your choice.