Preheat oven to 425 degrees.  Place red and green peppers on a baking sheet (whole) and spray with cooking spray. 

Press paprika onto surface of beef and place in a baking dish.  Roast for 30-40 minutes; until it reaches your desired doneness; see note below. Roast red and green bell peppers in the oven with the beef until tender; approximately 30 minutes.  Set peppers aside to cool when done and remove roast; allow to rest.  

While peppers and roast cook, prepare barley as directed on package.  Set aside. 

Cut beef into chunks and season with salt and pepper. Whisk together lime juice and olive oil, toss together with beef. Cut peppers into chunks and add to beef mixture along with barley, chopped green onion, and blueberries.  

Top lettuce with beef and serve.  If desired, add fresh avocado on top.