Tennessee Onions Recipe

Introduction

Tennessee Onions is a comforting baked onion casserole layered with a flavorful spice blend and three types of cheese. This dish transforms sweet Vidalia onions into a silky, cheesy delight perfect as a savory side or a vegetarian main.

Ingredients

• 2 teaspoons brown or granulated sugar
• 1 teaspoon chopped fresh thyme, or 1/2 teaspoon dried thyme, plus more for serving
• 1 teaspoon smoked paprika
• 1 teaspoon garlic powder
• 1/2 teaspoon mustard powder
• 1/4 teaspoon ground cayenne
• Salt and black pepper
• 1 lemon, zested and halved (optional)
• 3 pounds Vidalia onions (3 to 5 onions, depending on size)
• 1 tablespoon olive oil
• 1 cup (4 ounces) shredded sharp Cheddar
• 1 cup (4 ounces) shredded Swiss cheese
• 1/3 cup (1 ounce) grated Parmesan
• 3 tablespoons unsalted butter, cut into small cubes

Instructions

1. Step 1: Preheat your oven to 350 degrees Fahrenheit. In a small bowl, combine the brown sugar, thyme, smoked paprika, garlic powder, mustard powder, cayenne pepper, 1 teaspoon kosher salt (or 3/4 teaspoon fine salt), 1/4 teaspoon black pepper, and lemon zest if you are using it. This will be your spice blend.
2. Step 2: Slice the Vidalia onions crosswise into 1/4-inch-thick rings, making sure they are thin enough to become silky when baked. Separate the rings into individual pieces and place them in a large bowl. Toss gently with olive oil, the prepared spice blend, and the juice from half the lemon if you are using lemon, until the onions are well coated.
3. Step 3: Arrange half of the coated onions in the bottom of a 3-quart or 9-by-13-inch baking dish. Sprinkle with half of the shredded Cheddar and half of the Swiss cheese. Add the remaining onions on top, then layer all the remaining cheeses including the Parmesan. Dot the top evenly with the cubes of unsalted butter.
4. Step 4: Cover the baking dish tightly with aluminum foil. Bake for 45 minutes until the casserole is bubbling. Remove the foil, then continue baking uncovered for about 30 minutes more, or until the onions are soft and silky and the casserole has golden brown spots.
5. Step 5: Let the casserole cool for about 10 minutes. Sprinkle with additional thyme, then scoop onto plates to serve. If you used lemon, cut the remaining half into wedges for squeezing over the cheesy onions as desired.

Tips & Variations

• For a smokier flavor, try substituting smoked Gouda for the Swiss cheese.
• If you prefer a milder dish, reduce or omit the cayenne pepper.
• Using fresh thyme brightens the flavor, but dried thyme works well in a pinch.
• Ensure the onion slices are thin for the best tender, silky texture after baking.

Storage

Store leftover Tennessee Onions in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 300 degrees Fahrenheit until warmed through, or microwave in short intervals to avoid drying out the cheese.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I use a different type of onion?

Vidalia onions are ideal for their natural sweetness and tenderness, but you can substitute with other sweet onions like Walla Walla or Maui onions if necessary.

Is this dish vegetarian?

Yes, Tennessee Onions contains no meat and relies on cheese and spices for flavor, making it suitable for vegetarians who consume dairy.

Tennessee Onions Recipe

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★★★★★

4.5 from 412 reviews

• Author: Thomas
• Total Time: 1 hour 35 minutes
• Yield: 6 to 8 servings 1x
• Diet: Vegetarian

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Description

Tennessee Onions is a comforting, cheesy baked onion casserole featuring thinly sliced Vidalia onions layered with a flavorful spice blend, sharp Cheddar, Swiss, and Parmesan cheeses, then baked to golden perfection. This dish offers silky, tender onions infused with smoky, sweet, and slightly spicy notes, making it a delicious side or vegetarian main.

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Ingredients

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Spice Blend

• 2 teaspoons brown or granulated sugar
• 1 teaspoon chopped fresh thyme, or 1/2 teaspoon dried thyme, plus more for serving
• 1 teaspoon smoked paprika
• 1 teaspoon garlic powder
• 1/2 teaspoon mustard powder
• 1/4 teaspoon ground cayenne
• Salt and black pepper
• 1 lemon, zested and halved (optional)

Main Ingredients

• 3 pounds Vidalia onions (3 to 5 onions, depending on size)
• 1 tablespoon olive oil
• 1 cup (4 ounces) shredded sharp Cheddar cheese
• 1 cup (4 ounces) shredded Swiss cheese
• 1/3 cup (1 ounce) grated Parmesan cheese
• 3 tablespoons unsalted butter, cut into small cubes

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Instructions

1. Make the spice blend: Preheat your oven to 350°F (175°C). In a small bowl, mix together brown sugar, fresh or dried thyme, smoked paprika, garlic powder, mustard powder, cayenne pepper, kosher salt, black pepper, and lemon zest if using, creating a well-balanced, aromatic seasoning for the onions.
2. Prepare the onions: Thinly slice the Vidalia onions crosswise into 1/4-inch rings, separating them into individual rings. Place them in a large bowl and gently toss with olive oil, the prepared spice blend, and juice from half a lemon (if using), ensuring every piece is evenly coated with flavor.
3. Layer the casserole: Arrange half of the spiced onions in the bottom of a 9×13-inch or 3-quart baking dish. Sprinkle half of the sharp Cheddar and Swiss cheeses over the onions. Repeat layering with the remaining onions, cheeses, and sprinkle the grated Parmesan on top. Dot the surface with small cubes of unsalted butter to add richness.
4. Bake covered: Cover the dish tightly with aluminum foil to trap moisture. Bake in the preheated oven for 45 minutes until the casserole is bubbling, ensuring the onions become tender and begin melding with the cheeses.
5. Bake uncovered: Remove the foil and continue baking for another 30 minutes uncovered until the onions are soft and silky and the top has developed a golden-brown, slightly crispy crust.
6. Finish and serve: Allow the casserole to cool for 10 minutes to set. Sprinkle additional fresh thyme over the top. Serve warm, optionally with lemon wedges for squeezing over the cheesy onions for a bright finish.

Notes

• For best results, slice the onions very thinly to ensure they become silky rather than crunchy.
• If fresh thyme is unavailable, dried thyme works well; just adjust quantity accordingly.
• You can substitute other sweet onions if Vidalia onions are not available, but Vidalias provide the best sweetness.
• Leftovers can be refrigerated and gently reheated; the casserole may lose some crispness but remains flavorful.
• This dish pairs wonderfully with grilled meats or as a savory vegetarian main served with crusty bread.

• Prep Time: 20 minutes
• Cook Time: 1 hour 15 minutes
• Category: Side Dish
• Method: Baking
• Cuisine: Southern American

Keywords: Tennessee Onions, baked onions, cheesy onion casserole, Vidalia onion recipe, Southern side dish, cheesy baked vegetables