01 - Rinse the rice, quinoa, or farro under cold water. Combine grains, water or broth, and salt in a medium saucepan. Bring to a boil, reduce heat, cover, and simmer until tender—approximately 20 minutes for rice or quinoa, 30 minutes for farro. Fluff with a fork and set aside.
02 - Combine soy sauce, olive oil, lemon juice, minced garlic, and black pepper in a bowl. Add beef slices and toss thoroughly to coat. Allow to marinate for at least 15 minutes before cooking.
03 - Heat a large skillet or grill pan over medium-high heat. Add marinated beef and cook for 2-3 minutes per side until browned and just cooked through. Remove from heat and let rest briefly.
04 - Slice bell pepper, halve cherry tomatoes, dice cucumber, julienne carrots, and wash spinach or mixed greens while beef cooks.
05 - Whisk together olive oil, lemon juice, Dijon mustard, honey, salt, and pepper in a small bowl until emulsified.
06 - Divide cooked grains among four bowls. Arrange spinach or greens, bell pepper, tomatoes, cucumber, carrots, and sliced beef on top of each portion.
07 - Drizzle dressing evenly over each bowl. Garnish with sesame seeds, fresh herbs, and avocado slices if desired. Serve immediately.