Crack the eggs into a mixing bowl and whisk with almond milk, salt, and pepper until light and frothy.
Heat olive oil in a non-stick skillet over medium heat.
Add onions and red bell peppers and sauté for 3 minutes until softened.
Stir in the chopped spinach and cook until wilted, about 1 minute.
Pour in the egg mixture and let it sit undisturbed for 30 seconds.
Using a spatula, gently pull the edges toward the center, letting the uncooked egg flow underneath.
Once mostly set, sprinkle crumbled goat cheese over one side of the omelette.
Fold the omelette in half and cook for another 1–2 minutes.
Transfer to a plate and top with sliced avocado and optional herbs.