Chop onions and jalapeno peppers. Sweat them in a pan with canola oil.
Add white wine and vinegar, and let reduce.
Add heavy cream and let infuse for 30 minutes.
Strain the cream and whisk it into the melted cheese to make the cheese sauce.
Cut the potatoes into fries, soak in water, and fry twice to make crispy fries.
Make the fudge sauce by heating milk, butter, sugar, and bittersweet chocolate.
Blend the frozen custard or ice cream with the fudge sauce to make the black and white milkshake.
