Filling: Peel, core and cut pears into ½-inch (1 cm) cubes. In saucepan over medium-low heat, cook pears with sugar until tender and liquid is absorbed, 10 to 15 minutes. Mix cornstarch with 2 tsp (10 mL) water; stir into pears. Bring to boil; cook until thickened, about 1 minute. Transfer to bowl; let cool. Mix in chocolate.

In small bowl, dissolve 1 tsp (5 mL) of the sugar in half of the milk. Sprinkle in yeast; let stand for 10 minutes until frothy.

Meanwhile, in bowl of stand mixer fitted with paddle (or in bowl with wooden spoon), combine remaining sugar and milk, the butter, egg yolk and salt. Add yeast mixture; beat at lowest speed until smooth. Beat in flour, ½ cup (125 mL) at a time, scraping bowl as necessary, just until soft, sticky dough forms. Transfer dough to lightly buttered bowl; cover with plastic wrap. Refrigerate for at least 4 hours or overnight.

On lightly floured surface, roll out dough into¼-inch (5 mm) thick 14-inch (35 cm) square. Cut dough in half and each half into 4 pieces to make 8 equal rectangles. (Make-ahead: Cover with plastic wrap and refrigerate for up to 1 day.) Spoon ¼ cup (60 mL) filling in centre of one half of each rectangle; brush edges with egg white. Fold dough over filling; firmly press edges to seal.

In deep-fryer or deep saucepan, add enough oil to come 2 inches (5 cm) up side; heat to 360°F (185°C) or until 1-inch (2.5 cm) cube of white bread turns golden in 1 minute. Cook beignets, two at a time and turning often, until golden brown, 1-½ to 2 minutes. Using slotted spoon, transfer to paper towel-lined rack; let cool. Dust with icing sugar.