Which ingredient is NOT typically found in the Creamy Horseradish sauce?

Creamy horseradish sauce traditionally includes ingredients that contribute to its signature texture and flavor profile. Mayonnaise and sour cream are foundational components, providing the necessary creamy consistency and richness. Garlic can also be added for additional flavor, enhancing the sauce's taste.

Olive oil, while a popular ingredient in many dressings and sauces, is not typically associated with creamy horseradish sauce. Its inclusion would not align with the traditional recipe and objectives of creating a creamy, robust condiment specifically designed to complement dishes like roast beef. Therefore, seeing olive oil as an ingredient in this context is unusual, making it the correct answer to identify as not typically found in creamy horseradish sauce.