Gourmet Chicken Burgers with Caramelized Onion Focaccia Buns

In skillet, heat oil over medium heat; fry onions and garlic, stirring occasionally, until browned and most of the liquid is evaporated, about 15 minutes. Set aside.

Buns: In large bowl, dissolve sugar in warm water; sprinkle in yeast and let stand until frothy, about 10 minutes. Stir in 2 cups (500 mL) of the flour, 1 tbsp (15 mL) of the oil and salt to make sticky dough.

Turn out onto lightly floured surface; knead until smooth and elastic, about 8 minutes, adding as much of the remaining flour as necessary. Place in greased bowl, turning to grease all over. Cover with plastic wrap; let rise in warm draft-free place until doubled in bulk, about 1 hour.

Punch down dough; turn out onto lightly floured surface. Knead in thyme and half of the caramelized onion mixture. Divide into 7 portions. Shape each into ball, stretching and pinching dough underneath to make tops smooth. Place, 2 inches (5 cm) apart, on parchment paper–lined or greased baking sheets. Cover and let rise until doubled in bulk, 35 to 45 minutes.

Brush buns with remaining oil. Bake in centre of 400°F (200°C) oven until buns sound hollow when tapped on bottom, about 25 minutes. Let cool on rack. (Make-ahead: Store in airtight container for up to 24 hours.)

Chicken Burgers: Meanwhile, cut red pepper in half; broil, cut side down, on foil-lined rimmed baking sheet until softened and blackened, about 10 minutes. Let cool. Remove skin, stems and seeds; dice and set aside.

In food processor, pulse 1 of the buns to make coarse crumbs. Set aside.

In food processor in 2 batches, pulse chicken until coarsely ground. Transfer to large bowl. Mix in crumbs, red pepper, remaining caramelized onion mixture, basil, salt and pepper. Shape into six 1-inch (2.5 cm) thick patties. (Make-ahead: Layer between waxed paper in airtight container; refrigerate for up to 24 hours or freeze for up to 1 month.)

Place patties on greased grill over medium heat; close lid and grill, turning once, until digital thermometer inserted sideways into centre reads 185°F (85°C), about 20 minutes. Top each burger with basil leaf and cheese slice. Grill, covered, until cheese is melted, about 2 minutes. Sandwich each patty in bun.