Whisk together the flour, milk and beaten eggs. Once all the batter is mixed divide the mix into two separate jugs and season one with a good pinch of salt and pepper, and the other with the sugar and grate in the chocolate. Set both aside.
Get the 7-8 inch sandwich tins, make sure it's not a spring form one, and divide the veg oil between the two tins. Place both in a hot oven at 200C to get the oil really hot for about 8 minutes. Once the oil is spitting, pour in both batters. Place back in the oven and cook for 15 until golden and puffy.
To assemble the roast dinner Yorkshire, fill with all the roast dinner ingredients: Slices of roast chicken, blanched green beans, 4-6 crispy roast potatoes and carrots.
For the Yorkshire pudding sundae layer the sweet Yorkshire with scoops of ice cream, drizzle with the sauces, add in the wafers shaving over some nuts and brittle and finishing with sprinkles.