1 mango, chopped, or more to taste
1 banana, sliced, or more to taste
3/4 cup cold water, or as needed
1/2 cup chopped romaine lettuce
2 ice cubes
1 teaspoon flax seeds (optional)
1 tablespoon chia seeds
Blend mango, banana, water, lettuce, ice, and flax seeds together in a blender until smooth, about 2 minutes. Add chia seeds to mango mixture and stir. Let sit until smoothie thickens slightly, about 2 minutes.