What are Tennessee onions?

Tennessee onions is a creamy, cheesy casserole dish featuring layers of sliced sweet onions baked with a rich blend of mild cheddar, smoked Gouda, and Parmesan cheeses. It's seasoned with mustard powder, garlic powder, smoked paprika, and a touch of cayenne for subtle heat. No mayo is needed—the onions release natural moisture during baking, creating a bubbly, golden-topped side dish perfect for potlucks or holiday meals. This recipe serves 8-10 people and takes about 1.5 hours total, including prep. Slice 5-6 large onions thinly (about 1/8-inch) for even cooking, layer with cheese mixtures, and bake as directed for best results. It's vegetarian-friendly and pairs well with grilled meats or roasted chicken. (92 words)

Where did Tennessee onions come from?

Tennessee onions aren't a traditional dish from Tennessee—the name likely comes from its Southern-style appeal rather than a specific origin story. The recipe gained popularity online through food blogs and Pinterest, emphasizing Georgia-grown Vidalia onions for their signature sweetness. While unclear exactly who created it, it's become a modern comfort food staple in Southern cooking. You won't find it in old Tennessee cookbooks, but its simple ingredients make it easy to recreate at home. Use fresh Vidalias when in season (April-June) for peak flavor, or substitute other sweets like Walla Walla. This casserole highlights how regional ingredients inspire viral recipes. (98 words)

What onions are best for Tennessee onions casserole?

Sweet Vidalia onions are ideal for Tennessee onions due to their mild, juicy flavor that balances the cheeses without overpowering sharpness. Aim for 5-6 large ones (about 3-4 pounds total) to fill a 9x13-inch baking dish. If Vidalias aren't available, try other sweets like Maui, Texas Sweets, or Walla Walla—they caramelize beautifully during baking. Avoid strong varieties like yellow or red onions, as they can make the dish too pungent. Prep tip: Slice thinly with a mandoline for uniform layers, toss lightly with salt to draw out moisture, and let drain 30 minutes before assembling. This prevents a watery casserole. (102 words)

How long do you bake Tennessee onions?

Bake Tennessee onions covered with foil at 350°F for 45 minutes to soften the onions and meld flavors, until bubbling around edges. Remove foil and bake uncovered another 25-35 minutes until cheese is melted, golden, and slightly crispy on top—total time about 70-80 minutes. Check doneness by piercing onions with a knife; they should be tender. Let rest 10 minutes post-bake for easier slicing. Pro tip: Place dish on a sheet pan to catch drips. For food safety, internal temp should reach 165°F. High altitude? Add 5-10 minutes. Serves hot as a side—reheats well in oven at 325°F for 15 minutes. (108 words)

How do you store leftover Tennessee onions?

Store leftover Tennessee onions in an airtight container in the fridge for up to 4 days—the flavors deepen overnight. Reheat portions in a 325°F oven for 15-20 minutes until hot (avoid microwave to prevent sogginess). For longer storage, portion into freezer bags and freeze up to 2 months; thaw overnight in fridge before reheating. Note: Texture may soften slightly after freezing, but taste remains great. Don't leave at room temp over 2 hours. One 9x13 pan yields 8-10 servings (about 200 calories per serving, high in vitamin C from onions). Make-ahead: Assemble a day early, refrigerate, then bake fresh—adds convenience for gatherings. (104 words)

Tennessee Onions Recipe: Easy Cheesy Southern Delight

Name: Tennessee Onions
Prep time: 15 min
Cook time: 1 h 15 min
Total time: 1 h 30 min
Cuisine: Southern
Ingredients: – 3 pounds sweet onions, sliced into 1/4-inch-thick rings; – 1 1/2 teaspoons kosher salt; – 1 teaspoon dry mustard powder; – 1 teaspoon garlic powder; – 1 teaspoon smoked paprika; – 1/4 teaspoon cayenne pepper (optional); – 4 ounces mild cheddar cheese shredded; – 4 ounces smoked Gouda or cheddar cheese shredded; – 1 1/4 ounces grated Parmesan cheese; – 4 tablespoons unsalted butter diced; – 2 tablespoons finely chopped fresh parsley leaves (optional)

Ingredients

– 3 pounds sweet onions, sliced into 1/4-inch-thick rings

– 1 1/2 teaspoons kosher salt

– 1 teaspoon dry mustard powder

– 1 teaspoon garlic powder

– 1 teaspoon smoked paprika

– 1/4 teaspoon cayenne pepper (optional)

– 4 ounces mild cheddar cheese shredded

– 4 ounces smoked Gouda or cheddar cheese shredded

– 1 1/4 ounces grated Parmesan cheese

– 4 tablespoons unsalted butter diced

– 2 tablespoons finely chopped fresh parsley leaves (optional)

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Instructions

1-First Step: Preheat and Prep the Dish Begin by preheating your oven to 350 degrees Fahrenheit. Grease a 9×13-inch baking dish with cooking spray to prevent sticking. This step sets the stage for even baking and makes cleanup a breeze, especially if you’re preparing for a busy family dinner.

2-Second Step: Season the Onions In a large bowl, toss the 3 pounds of sliced sweet onions with 1 1/2 teaspoons kosher salt, 1 teaspoon dry mustard powder, 1 teaspoon garlic powder, 1 teaspoon smoked paprika, and 1/4 teaspoon cayenne pepper if you want some spice. This mixing ensures the onions absorb the flavors, creating a savory base that adapts well to dietary tweaks like reducing salt for low-sodium diets.

3-Third Step: Layer the Ingredients Spread half of the seasoned onions evenly in the prepared baking dish. Sprinkle half of the 4 ounces shredded mild cheddar and 4 ounces smoked Gouda over the top. Add the remaining onions, then top with the rest of the cheddar, Gouda, and 1 1/4 ounces grated Parmesan cheese. For variations, you could swap cheeses here for a different twist while keeping the Tennessee Onions true to its roots.

4-Fourth Step: Add Butter and Cover Dot the top with 4 tablespoons of diced unsalted butter for that extra melt-in-your-mouth goodness. Cover the dish tightly with foil to help the onions soften without drying out. This step takes about 45 minutes in the oven, allowing the flavors to meld perfectly for a dish that serves a crowd.

5-Fifth Step: Bake Uncovered Bake the covered dish for 45 minutes until the onions are softened and bubbling. Then, remove the foil and bake for another 30 minutes until the cheese melts and browns in spots. Check for doneness by ensuring the onions are tender, which makes this ideal for food enthusiasts exploring Tennessee Onions variations.

6-Final Step: Garnish and Serve Once out of the oven, let it rest for a few minutes, then garnish with 2 tablespoons of finely chopped fresh parsley if desired. Serve hot as a side with dishes like beef tater tot casserole for a full meal. This recipe takes about 15 minutes to prepare and 1 hour 15 minutes to cook, making it perfect for busy parents or community events.

Last Step:

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Notes

🧅 Select sweet onion varieties like Vidalia for their mild, caramel-like flavor that shines when baked, enhancing the dish’s natural sweetness without overpowering sharpness for a crowd-pleasing Southern staple.
🔥 Adjust the cayenne pepper to taste or omit for milder palates, but include smoked paprika and garlic powder to infuse savory depth that complements the cheese layers without needing extra steps.
🧀 Cover during the initial bake to steam and tenderize the onions fully, then uncover to achieve that irresistible bubbly, browned cheese crust—refrigerate leftovers up to 4 days and reheat at 350°F for 15 minutes to revive textures.

Author: Brandi Oshea
Prep Time: 15 minutes
Cook Time: 1 hour 15 minutes
Category: Side Dishes
Method: Baked
Cuisine: Southern
Diet: Vegetarian

Nutrition

Serving Size: 1/10 of casserole
Calories: 211
Sugar: 7g
Sodium: 399mg
Fat: 15.1g
Saturated Fat: 7.8g
Unsaturated Fat: 7.3g
Trans Fat: 0g
Carbohydrates: 12.1g
Fiber: 1.4g
Protein: 7.8g
Cholesterol: 30mg