Pissaladière - Savoury puff pastry with onions, anchovies and olives

Ingredients

• 1lb Puff pastry (total weight (Fresh dough or frozen)
• All-purpose flour (for the work surface)
• 2 3/4 cups all-purpose flour
• 3/4 cups cake flour
• 2 tsp salt
• 1/4 cup canola oil
• 1 cup ice water
• 3 sticks cold unsalted butter
• 1/4 cup olive oil
• 3lbs yellow or sweet onions halved and thinly sliced
• 1 tsp chopped fresh thyme leaves
• fine sea salt & fresh ground pepper to taste
• 1 large egg
• 1 tbsp water
• 24 Anchovy filets
• 1/2 cup Niçoise olives or black olives, pitted
• 6 basil leaves torn by hand