In mixing bowl mix eggs, milk, oregano, salt and pepper with fork until blended.
Spray 8-inch non stick skillet or omelet pan. Heat over medium-high heat.
Pour eggs into pan. As egg cooks gently lift edges with spatula to allow uncooked eggs to run under, when some what set run spatula around edges, then right under and flip.
Let stand over heat a few seconds to lightly brown bottom of omelet.
Sprinkle with cheese and chilies.
Fold portion of omelet just to center. Allow for a portion of the omelet to slide up side of pan. Turn omelet onto warm plate, flipping folded portion of omelet over so it rolls over the bottom. Top with sour cream tomatoes and sprinkle with cilantro and garnish with olives and avocado.