- Preheat oven to 350°F (180°C). Line 8-in.(20-cm) square baking pan with parchment paper, allowing for overhang on sides. Set aside. Cook bacon in non-stick skillet over medium heat until golden brown and crisp, about 8 min. Drain on paper towels.
- In bowl, whisk eggs with milk, chives, salt and pepper. Stir in bacon. Pour frittata mixture into lined baking pan. Bake 20 min. until egg mixture is set. Cool slightly; cut into 12 pieces.
- Meanwhile, mix mustard with maple syrup. Split baguette in half lengthwise; cut into 12 sections. Fill each with piece of frittata, strip of cheese, arugula and drizzle of maple mustard.
Tip: Substitute Dijon mustard with grainy mustard.