Prepare all ingredients as instructed.
Heat water to 175–185°F (80–85°C), just before boiling. Remove from heat, add green tea bags, and steep for 3 to 5 minutes. Remove tea bags and keep warm.
Heat olive oil in a nonstick skillet over medium heat. Add yellow onion and red bell pepper and sauté until softened. Add spinach and cook until wilted.
Add beaten eggs and black beans to the skillet and scramble gently until eggs are just set. Season with salt and black pepper. Remove from heat.
Warm whole wheat tortillas in a dry skillet or microwave until pliable.
Spoon the egg and vegetable mixture onto the tortillas. Top with cheddar cheese and avocado if using. Fold and roll tightly.
Combine pear slices with ground cinnamon and toasted walnuts.
Serve the burrito with pear, green tea, and milk.