Heat the milk, heavy cream and lemon juice on a heavy bottom pan over medium heat, stirring occasionally. As milk will start heating the curd will start separating from the whey, slowly it will separate into thick curds and whey will separate.
Once the milk fat has separated from the whey, drain the whey using a strainer line with cheesecloth, or muslin cloth.
Wrap the curds in a muslin cloth, rinse under cold water, and squeeze well. This process takes out the sourness from the lemon.
Heat the frying pan on medium. Add butter and let it melt.
Next add milk curd, and milk powder. Mix it well.
Cook mixture on medium heat stirring continuously until mixture starts leaving the sides of the frying pan and becomes like soft dough. This should take about 12 minutes. Now this is known as khoya.
Transfer the khoya into a bowl and let it cool off until khoya becomes just lukewarm.
Mix the sugar and cardamom powder into the khoya and knead it for about a minute until everything blends together and become soft dough. Note: if you mix the sugar while khoya is hot that will make burfi soft.
Transfer mixture to the greased plate and press firmly into a square or rectangular shape, approximately 1/2 inch high.
Let the burfi sit for about one hour before slicing I prefer cutting in about 1-1/2 inch squares.
For garnishing put few pieces of sliced pistachios on every piece burfi.