Tomatoes with oil. Spread onto sheet pan, cut sides up. Bake in 275°F (140°C) standard oven 2 hours or until slightly shriveled. Cool.
For each Flatbread:
1/4 cup (50 mL) dressing onto 1 flatbread; place on parchment paper-lined half sheet pan. Top with 1 cup (250 mL) cheese, 1/4 cup (50 mL) onions, 1/2 cup (125 mL) roasted tomatoes and 0.75 oz (20 g) bacon.
In 450°F (230°C) standard oven 10 min. or until cheese is melted and bubbly. Cut into 8 wedges. Top with 1/2 cup (125 mL) arugula and drizzle with 2 Tbsp. (30 mL) remaining dressing.