Strudel dough: In a medium bowl, add the water, oil, vinegar and salt. Then add about half of the flour and mix for about a minute to allow the gluten in the flour to develop.
Once well combined add the remaining flour and then knead the dough in the bowl or on your work surface until nice and smooth. (approx 5 minutes) This is important to help the gluten develop further and for it to be elastic enough for stretching.The dough should be moist but not sticky. If it is too sticky add just a little more flour. If the dough becomes too dry it will crack and split when shaping. Shape the dough into a ball and place it into a clean bowl. Coat the dough in a little oil to stop it from drying out and cover the bowl with a lid or clingfilm.
Leave the dough covered for 30-60 minutes at room temperature or alternatively, place it in the fridge overnight and then, the following day, remove and leave it to come to room temperature (approx 20-30 minutes).
Breadcrumbs: Toast the bread crumbs in a frying pan on low heat, stirring continuously to stop them from browning. Once the bread crumbs are a nice golden colour, transfer them to a bowl and leave to cool. Apple filling: Cut the apples into 2cm pieces and place them in a large bowl. Coat the apple in a little lemon juice to stop them from browning.
Add the blueberries, pecans, brown sugar and cinnamon.
Rolling and stretching the dough: Flour a work surface and roll the dough out into a rectangle. Approximately, 30x40cm (12x16 inches).
Then lay a clean tea towel onto the table, dust with a little flour and place the dough on top of it.
Using the back of your hand and knuckle, place it under the dough and between the cloth and stretch the dough from the center out. Sometimes it helps to put your other hand in the center of the dough to stop it from moving around.Gently stretch the dough from the inside to the outside, working your way around all the edges.Every now and again, you may need to pull the edges of the dough out gently to keep the rectangular shape. Stretch it until it starts to look paper-thin and translucent. You should be able to read a note written on a piece of paper through the dough.
Once it is ready, brush one half of the dough with oil.
Preheat the oven to 170°C fan / 375°F / Gas 5.
Filling the strudel: Cover the half of the strudel that has not been oiled, with the breadcrumbs, leaving a 2cm (1inch) gap at the edge.Scatter the apple mix over the top of the breadcrumbs evenly, but not wider than 30cm. Also, avoid adding any excess liquid that has collected in the bottom of the bowl. (We don't want a soggy bottom.) Fold in the sides of the dough over the filling to prevent the filling from coming out at the edge while rolling.
Using a tea towel, roll the dough from the end of the filling. Place a piece of baking paper or parchment at the end and gently roll the strudel onto it seam side down. Transfer to a baking tray and brush with more oil.
Baking: Place the tray in the center of the oven and bake for 30-35 minutes until golden brown.
Once baked, remove from the oven and either serve with ice cream or leave to cool, then dust with icing sugar and serve.