Preheat the Oven: Start by preheating your oven to 375°F (190°C). This ensures that the casserole cooks evenly.
Blanch the Green Beans: Bring a large pot of salted water to a boil. Add the green beans and blanch for about 3 minutes until they are bright green but still crisp. Drain and immediately plunge into ice water to stop the cooking process. Drain again and set aside.
Cook the Potatoes: In the same pot, add the potatoes and cover with water. Bring to a boil and cook until just tender, about 10 minutes. Drain and set aside.
Cooking the Sausage and Vegetables:
Brown the Sausage: In a large skillet over medium heat, add the olive oil and sausage slices. Cook until the sausage is nicely browned on both sides. Remove the sausage from the skillet and set aside.
Sauté the Vegetables: In the same skillet, add the diced onion and minced garlic. Sauté until the onion is translucent and the garlic is fragrant.
Combine Sausage, Vegetables, and Potatoes: In a large mixing bowl, combine the blanched green beans, cooked potatoes, browned sausage, sautéed onion, and garlic. Gently mix to combine.
Creating the Sauce:
Make the Sauce: In the same skillet, add the chicken broth, heavy cream, paprika, and thyme. Bring to a simmer and let it cook for about 5 minutes, until slightly thickened. Season with salt and pepper to taste.
Combine Everything: Pour the sauce over the sausage, vegetables, and potatoes in the mixing bowl. Add the grated cheese and gently mix until everything is evenly coated.