Sweet Potato Ground Beef Casserole Recipe

This sweet potato ground beef casserole is hearty, cheesy, and packed with flavor, perfect for make-ahead meals or easy weeknight dinners.

Sweet potatoes are equally requested as regular potatoes in our home, which says a lot considering my family's love for potatoes. Between my sweet potato Thanksgiving stuffing that's become a holiday essential and the sweet potato casserole with hazelnuts that my husband asks for at least once a month, I'm always looking for new ways to use this orange vegetable. This sweet potato ground beef casserole is the perfect recipe when we want sweet potatoes as part of the main dish.

Unlike my other sweet potato recipes, this one leans into the savory side with that seasoned ground beef with an umami punch thanks to the white miso. The sweet potato mash on top adds just enough natural sweetness to complement  the meaty flavors underneath, while the melted mozzarella creates those golden bubbles on top... good thing my kids love the middle part and always go for the corner pieces.

I typically make this on Sundays when I want something filling but doesn't need constant attention. The timing works perfectly with only 45 minutes total and most of that being passive oven time. 

My daughter has claimed this as "her recipe" because she helped me by suggesting we add more cheese on top. She was absolutely right, that extra layer of mozzarella creates these golden, crispy spots that everyone fights over. Now she insists on being my assistant every time we make it, carefully sprinkling the shredded cheese with concentration to make them even.

This has become one of my go-to tricks for getting more vegetables into our week. The sweet potatoes are doing all the heavy lifting nutrition-wise, but since they're mashed up and covered in melted cheese, everyone just sees it as regular comfort food. I make this at least twice a month now because it helps me feel better about all the pizza and takeout we end up having during crazy busy weeks.

Ingredients

Sweet potatoes – Make up the mash layer with natural sweetness and a smooth texture. I’ve tried using regular potatoes alone, but the dish loses character without the sweet potatoes. Roasting brings out more flavor, though boiling is faster and works fine.

Potato (optional) – Balances the sweetness of the sweet potatoes and adds a fluffier texture. Helpful if you're serving people who prefer a more neutral mash.

Milk – Loosens the mash and makes it smoother. Oat and almond milk work if needed, but dairy gives a creamier result.

Butter – Adds richness to the mashed layer. Salted or unsalted both work depending on what's on hand.

Ground beef – Forms the hearty base of the filling. I’ve tested both lean and regular, and a bit of fat gives better browning and flavor. 

Onion – Builds depth in the beef mixture and keeps it from drying out. I once skipped it and the filling tasted flat. Yellow or white onions both work well for this.

Red bell pepper – Adds mild crunch and bright color. I’ve tried green peppers too, but they turned out too bitter against the sweetness of the mash.

White miso – Adds savory depth and helps balance the layers. I tested soy sauce and bouillon as subs, but miso gave a more rounded flavor without over-salting.

Mozzarella cheese – Finishes the casserole with a golden, gooey top. I’ve used cheddar before, but it overwhelmed the other flavors. Mozzarella melts better and stays in the background.

See the recipe card for exact quantities.

Step-by-step Instructions

This casserole brings together a savory beef and vegetable filling with a creamy mashed sweet potato topping. It’s simple to make and great for a weeknight dinner or meal prep.

Cook the Potatoes

Peel the sweet potatoes and the optional regular potato, then cut them into large chunks. Place them in a pot of boiling water or set them in a steamer basket over boiling water. Cook for 15 to 20 minutes, or until the pieces are soft and easily pierced with a fork. Drain well and set aside.

Make the Mashed Topping

Transfer the drained potatoes to a large mixing bowl. Add the milk, butter, salt, pepper, and a small pinch of nutmeg. Mash by hand or use an immersion blender until smooth and creamy. Taste and adjust seasoning if needed. Set aside while you make the filling.

Cook the Beef Mixture

In a large skillet over medium heat, add the ground beef along with the salt, garlic powder, paprika, and chili flakes. Cook for 5 to 6 minutes, breaking up the meat with a spoon, until it starts to brown.

Add Vegetables and Miso

Add the diced onion and red bell pepper to the skillet. Continue cooking for another 5 to 7 minutes, until the beef is fully cooked and the vegetables are soft. Stir in the white miso until fully combined. Once everything is mixed well, remove the skillet from heat.

Preheat the Oven

Preheat your oven to 200°C (400°F) while you assemble the casserole.

Assemble the Casserole

Spread the beef and vegetable mixture evenly in the bottom of an oven-safe baking dish. Sprinkle a small amount of mozzarella cheese over the beef layer. Then spoon the mashed sweet potato mixture on top and spread it out evenly to cover. Finish by adding the remaining mozzarella cheese over the top.

Bake and Serve

Place the dish in the oven and bake for 15 to 20 minutes, or until the cheese is melted and lightly browned. Remove from the oven and let it sit for a few minutes before serving. Serve warm, straight from the dish.

Storage

This casserole can be assembled a day in advance and stored in the refrigerator, covered tightly, then baked just before serving. Add 5 to 10 extra minutes if baking straight from the fridge. Leftovers keep well in an airtight container in the fridge for up to 3 days and can be reheated in the microwave or oven. It also freezes well. Once fully cooled, wrap it tightly and freeze for up to 2 months. Thaw overnight in the fridge before reheating.

Recipe