Peel and cut the starchy potatoes into 1-inch cubes. Place in a large pot, cover with cold water, and season with salt. Add bay leaves and bring to a boil, then simmer for about 20 minutes.

While boiling, heat a tablespoon of butter or oil in a skillet. Sauté chopped shallots and garlic until fragrant, then add chopped curly kale with a splash of water. Cover and cook until tender, about 5-7 minutes.

Drain the potatoes, discard bay leaves, and return to pot. Add butter, warm milk, salt, pepper, and nutmeg. Mash until smooth and creamy.

Fold the sautéed kale mixture into the mashed potatoes until combined. Adjust seasoning as needed.

Prepare the sausage by grilling or sautéing until golden brown, about 5-7 minutes.

Serve the creamy Stamppot topped with sausage slices, optionally drizzling with olive oil.