Bagel Breakfast Casserole with Kielbasa
Bagels, smoky kielbasa, and sharp cheddar bake into one rich, cheesy overnight breakfast casserole that’s easy to make ahead and perfect for feeding a crowd.
Servings 12
Calories 414kcal
Equipment
- baking dish 9x13 (23x33). Roomy enough for all the layers.
- nonstick skillet Browns the kielbasa and cooks the veggies.
- mixing bowls To whisk the custard.
- whisk For beating eggs and cream together.
Ingredients
- 1 lb (454 g) onion bagels cubed
- cooking spray
- 14 oz (397 g) kielbasa halved lengthwise and sliced
- 1 tbsp (15 ml) vegetable oil
- 10 oz (283 g) sliced mushrooms
- 1 large shallot finely minced
- 10 large eggs
- 1 cup (240 ml) heavy cream
- ½ cup (120 ml) whole milk
- ½ cup (120 ml) low-sodium beef broth
- ½ cup (120 g) spicy brown mustard
- ¼ cup (25 g) sliced green onions
- 1 tsp (6 g) table salt
- 1 tsp coarsley ground black pepper
- 8 oz (227 g) shredded extra-sharp cheddar cheese divided
Instructions
- Place the bagel cubes on a baking sheet and let them stale overnight until completely dry, about 24 hours. Alternatively, bake them in a 350°F (175°C) oven for 15 to 20 minutes.1 lb (454 g) onion bagels
- Preheat the oven to 375°F (190°C) and coat a 9×13-inch (23×33 cm) baking dish with nonstick spray.cooking spray
- In a nonstick pan over medium heat, brown the kielbasa until the edges are crisp. Remove with a slotted spoon onto a paper towel lined plate.14 oz (397 g) kielbasa
- Add the oil to the same pan, then stir in the mushrooms and cook until they release their liquid and it evaporates. Stir in the shallot and cook until softened, 1 to 2 minutes. Remove from the heat.1 tbsp (15 ml) vegetable oil, 10 oz (283 g) sliced mushrooms, 1 large shallot
- In a large bowl, whisk together the eggs, cream, milk, broth, mustard, green onion, salt, and pepper.10 large eggs, 1 cup (240 ml) heavy cream, ½ cup (120 ml) whole milk, ½ cup (120 ml) low-sodium beef broth, ½ cup (120 g) spicy brown mustard, ¼ cup (25 g) sliced green onions, 1 tsp (6 g) table salt, 1 tsp coarsley ground black pepper
- Add the bagel cubes to the bowl and toss to coat in the mixture.
- Fold in the kielbasa, mushroom-shallot mixture, and half of the cheese. Transfer everything to the prepared baking dish, cover, and refrigerate overnight.8 oz (227 g) shredded extra-sharp cheddar cheese
- When ready to bake, sprinkle the remaining cheese over the top. Bake for 45 to 60 minutes, or until an instant-read thermometer inserted in the center registers 160°F (71°C).
- Let the casserole rest for 20 minutes before serving.
Notes
- Bagels make this sturdier than most breakfast casseroles, with a chewy bite that doesn’t go soggy.
- For a true cheesy breakfast casserole, mix cheddar with gouda or mozzarella.
- Kielbasa is classic here, but any smoked sausage works in this sausage breakfast casserole.
- This is the kind of make-ahead breakfast casserole that shines on weekends or holidays.
- Bell peppers, spinach, or zucchini can be folded in if you like more of an egg casserole feel.
Nutrition
Serving: 220g | Calories: 414kcal | Carbohydrates: 23g | Protein: 17g | Fat: 30g | Saturated Fat: 14g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 10g | Cholesterol: 216mg | Sodium: 875mg | Potassium: 274mg | Fiber: 1g | Sugar: 3g | Vitamin A: 825IU | Vitamin C: 1mg | Calcium: 200mg | Iron: 2mg