Cut the chicken breasts in long thin strips.
Place in a bowl with the cumin powder, lime juice, olive oil and salt. Toss to coat.
Cover and refrigerate for 1 hour or overnight.
Preheat the oven to 450F / 230C. Line a baking sheet with parchment paper or silicone baking mat. Place the red bell peppers cut side down on the prepared sheet.
Roast 25 minutes or until the skins are wrinkled and charred. Remove from the oven.
Let cool completely and peel off the skins. Cut in long strips. Add to the chicken mixture. Coat a large grill pan with non-stick cooking spray. Place over medium heat.
Add the chicken mixture and cook thoroughly – about 10 minutes.
Place two tortillas on each plate. Spoon some of the guacamole.
Top with chicken and garnish with fresh cilantro.