Rinse and dry spinach, remove large stems, and chop into approximately 1/2" pieces.
Place chopped spinach in a medium mixing bowl.
Chop sun dried tomatoes into approximately 1/4" pieces, add to bowl with the spinach.
To the mixing bowl, add oil from the sun dried tomato jar and then add feta, salt, pepper, and oregano. Gentle stir to combine and coat ingredients with oil & seasonings.
Butterfly or horizontally cut the chicken breasts.
One chicken slice at a time, add about 1/3 cup of the feta mixture to one side of the chicken breast. Fold chicken to wrap the feta mixture and secure with toothpicks.
Over medium high heat, heat 2 tablespoons olive oil in a large skillet.
Carefully add chicken wraps to pan and cover.
Let chicken cook for 4 minutes, reduce heat to medium-low, turn each chicken wrap carefully to cook the other side, and cover.
Let chicken cook for an additional 5 minutes until cooked through (safe cooked chicken temp is 165°F).
Remove from heat and discard toothpicks before serving.