Finely dice the carrots and red bell pepper, then finely chop the green onions.

Crack all 10 large eggs into the large mixing bowl. Add the salt, black pepper, and toasted sesame oil.

Whisk the egg mixture until fully combined. Stir in the carrots, red bell pepper, green onions, and spinach.

Heat the avocado oil in a 10- or 12-inch nonstick skillet over medium-low heat. Tilt the skillet to coat its surface.

Pour about 1/2 cup of the egg mixture into the skillet. Tilt the skillet to spread it into a thin, even layer.

Cook the egg layer for 1 to 2 minutes. Stop cooking when it is mostly set but remains slightly moist on top.

Roll the cooked egg from one side toward the other using the silicone spatula. Stop just before reaching the opposite edge.

Slide the partial egg roll back to the starting side of the skillet. Pour another 1/2 cup of the egg mixture into the empty space.

Cook the new egg layer until mostly set. Roll the existing omelet over the new layer with the silicone spatula.

Repeat adding 1/2 cup egg mixture and rolling the omelet. Continue until all of the egg mixture has been used.

Cook the finished omelet roll for 1 to 2 more minutes. Turn it gently to cook the center and lightly brown the outside.

Transfer the rolled omelet to the cutting board and rest it for 5 minutes. Slice into thick rounds and serve warm.