The white sauce is maybe a roux? You make it with a few spoonfuls of butter- say 3 T, melt in a small saucepan but be careful not to burn it. Add in an equal amount of flour, it'll make a paste that again, you don't want to let burn. Stir that for about a minute, then add 2 c of milk, stirring til it thickens. If you like your sauce cheesy, add about 1.5 c of cheddar to it, stir til it melts. Makes a really good white sauce. Maybe add a bit of curry or paprika or pepper at the end, whatever you like. When I make a roux I line up all the ingredients because if I turn my back it makes a mess.