Take your 1 3/4 cup (400 ml.) whole milk, 4/5 cup (200 ml.) water, 2 cup granulated sugar in a medium saucepan and heat it until combined and sugar dissolves.
Melt your 1 pack (250 gr. / 9 oz.) margarine or butter in a medium pot. Add your 500 gr. (18 oz.) semolina to your melted butter and cook it stirring continuously until it turns brown. Browning step is very important for semolina halva because it gives the halva its colour.
Add your syrup to your browned semolina very carefully and cover your pot immediately to avoid burning yourself. Wait a little until halva is not splashy anymore, uncover your pan and then stir your halva for about 6-7 minutes at slow heat until it gets thick and gets its dark colour.
Turn of your heat, put a paper towel on top of your pot, cover your pot and rest your halva until cool. (Your halva is ready and you can also eat it at this point if you want without any ice cream : ) )
Take a soup bowl and put a plastic wrap in it to be able to take off the halva from easier later. Spread a line of halva on your bowl by leaving the middle empty. Fill the empty side with vanilla ice cream and cover all the top of the bowl with halva. (as you can see in below video.) Turn it upside down on your serving plate and remove the bowl carefully.