Apple Tart with Mustard Custard and Cheese Streusel

Ingredients

• 0.3 lb butter 
• 10 servings butter pastry 
• 10 servings cheese streusel 
• 1.5 teaspoons mustard dry
• 1 large eggs 
• 2.5 tablespoons flour all-purpose
• 2 tablespoons mustard prepared (see notes)
• 1.8 lb golden delicious apples peeled coarsely chopped
• 0.7 cup sugar 

Equipment

• bowl
• frying pan
• baking sheet
• oven
• blender
• aluminum foil

Directions

1. In a 1- to 1 1/2-quart pan over medium heat, melt butter and stir often until golden brown, 5 to 7 minutes.
2. Remove from heat.
3. Meanwhile, in a bowl, with a mixer on medium speed, beat sugar, flour, and dry mustard until well blended. Beat in prepared mustard and egg.
4. Add hot butter in a thin, steady stream, beating until mixture is cool, 2 to 3 minutes. Gently stir in apples.
5. Spoon apple mixture into warm baked butter pastry and spread level.
6. Sprinkle cheese streusel evenly over filling. Set tart on a foil-lined 12- by 15-inch baking sheet.
7. Bake in a 350 regular or convection oven until streusel is golden brown, 45 to 55 minutes. If tart edges brown excessively, drape lightly with foil. Cool on a rack about 1 1/2 hours.
8. Remove pan rim.
9. Cut tart into wedges.