To prepare the beef: Place the beef strips in a bowl. Mix together the cumin, some freshly ground black pepper and 2 tablespoons oil. Stir through the beef and leave to marinade for 15 minutes if you have time.
To make the salad: Add the tomatoes, scallions, beans, corn and rice into a large bowl, season with a little salt and black pepper. Set aside while you make the dressing.
To make the dressing: In a bowl mix together the coriander leaves, garlic, chilli, lime juice and zest, oil and smoked paprika. Add about half the dressing to the salad and mix well.
To cook the beef: Heat a grill pan or frying pan until really hot. Season the beef with a little salt then add half the beef strips to the hot pan and cook for a couple of minutes, stirring all the time. You will need to this in 2 batches.
To serve: Divide the lettuce between four serving bowls. Then add the salad, top with avocado slices and the beef and drizzle over the rest of the dressing.