Steps
1. Heat olive oil in a small pan over medium heat.
2. Add sliced onions and sauté until soft and translucent, about 3-4 minutes.
3. Add corn kernels to the pan and cook for another 2 minutes until warmed through. Season with a pinch of salt and pepper.
4. In a bowl, combine cooked rice, sautéed onions and corn, and canned tuna.
5. Gently fold in diced avocado and drizzle with lemon juice.
6. Season the bowl with salt and pepper to taste.
7. Garnish with chopped cilantro if desired and serve immediately.