First line an aluminium foil or parchment paper in a 6 x 6 inch square pan. The foil or parchment paper has to cover all the sides and keep some extra on the top.
Chop the chocolate. Alternatively you could keep the chocolate bar in a ziplock bag and with a pestle, break the chocolate.
Take the chopped chocolate in a bowl or a frying pan. Add the condensed milk and butter. You can use either salted or unsalted butter. Set the bowl or frying pan aside.
In a sauce pan or pot heat 1 to 1.5 cups water till it becomes hot and begins to boil.
Lower the heat and place the frying pan or bowl containing the chocolate, condensed milk and butter on the pan.
Stir and allow the chocolate to melt. Continuously stir the fudge mixture while melting the chocolate.
Once all the chocolate is melted, switch off the heat.
Quickly add chopped walnuts and vanilla extract or vanilla powder. Mix very well.
Setting the fudge
Then pour the entire chocolate fudge mixture in the pan lined with the aluminium foil or parchment paper.
Let the fudge cool at room temperature. Do not cover the pan.
Once the fudge has cooled at room temperature, cover the pan and refrigerate the fudge for 2 to 3 hours or overnight till it sets completely.
Later remove the chocolate fudge along with the foil and place it on a chopping board. Remove the foil from the bottom and sides.
Slice the chocolate fudge into squares or rectangles.
Serve these chocolate fudge or wrap them in foil or butter paper and keep covered in a jar or box in the fridge.
Lining your pan or tray: Always line your pan or tray with a foil or parchment paper when making any fudge. Do keep some extra paper or foil on the sides of the pan so that you can easily lift it when the fudge is set.
Tempering chocolate: Chocolate needs to be tempered correctly for a smooth and glossy texture. The best method to temper the chocolate is with the double boiler as shown in the recipe. You could even microwave the chocolate for a few minutes till it melts.
Roasting Nuts: If you prefer you can lightly toast the nuts. For the nuts you could use pistachios, almonds, walnuts, pecans and pine nuts.
Refrigeration: You do need to refrigerate the fudge for it to set completely and give you neat squares or cubes.
Scaling: You could easily halve or double this recipe.
Replace ghee (clarified butter) with butter.
Use semi-sweet chocolate, dark chocolate, white chocolate or chocolate chips instead of milk chocolate.
In place of sweetened condensed milk use evaporated milk but add some icing sugar according to your taste.