Preheat the fryer to 375 degrees F.
In a mixing bowl, whisk together the flour, cornstarch, egg, and soda water. Mix well to make a smooth batter. Season with salt and cayenne. Dip each floret into the batter, shaking off any excess. Carefully add the battered broccoli to the oil and fry until crispy, about 2 to 3 minutes. Remove and drain on paper towels. Season with salt.
In a large saucepan, over medium heat, melt the butter. Stir in the flour and cook, stirring constantly for 4 minutes to make a blond roux. Add the onions and celery. Season with salt and pepper. Continue to cook for 2 minutes or until the vegetables are wilted. Stir in the beer and stock. Bring the mixture to a boil, reduce to a simmer and cook for 30 minutes. Stir in the milk and cheese. Continue to cook for 10 minutes. Season with salt and hot sauce. Reduce the heat and keep warm.
To serve, ladle the soup into each bowl. Garnish with the Tempura Florets and parsley.