1. Drain the tofu and dice into large cubes. Set aside in a shallow baking pan.In a small mixing bowl, combine the olive oil, vinegar, cumin, and chili powder mix thoroughly.
2. Pour the olive oil marinade over the cubes and let sit for at least 1 hour.In a large salad bowl, lightly toss the onions, tomatoes, avocados, and mixed greens.Top the salad with the marinated tofu (using any residual marinade as dressing) and garnish with the blue chips.