"Create a beginner-friendly green bean casserole that is dairy-free, corn-free, and gluten-free, using the previously requested dairy-free cream of mushroom soup style as the creamy mushroom component. Make it suitable for a household of 3, quick and easy, minimal processing, and use imperial units. Include a simple crispy topping that avoids gluten, dairy, corn, soy, nuts, and sesame. Keep it oven-friendly and classic in flavor, but safe for the listed allergies."