High-Protein Cheesy Onion Rings
Crispy edges, melty cheese, and sweet caramelized onion — a high-protein low-carb take on classic onion rings
These are not traditional battered onion rings. Thick onion slices are layered with cheese and baked (or air-fried) until the edges crisp and the cheese turns golden and stretchy. The result is a high-protein, keto-friendly side or snack that delivers 22 g of protein and only 8 g net carbs per serving.
One sheet pan, completely sugar-free, and ready to satisfy that onion-ring craving without the carbs.
Why you’ll love these onion rings
- 22g protein per serving — far higher than traditional onion rings
- Only 8g net carbs and fully keto-friendly
- Crispy edges with gooey melted cheese
- No breading or deep frying required
- Ready in about 30 minutes
- Perfect as a side, snack, or appetizer
Health notes
- High protein: Cheese is the main protein source and keeps you satisfied.
- Low carb: No flour coating — just onion and cheese.
- Keto-friendly: Fits most low-carb and keto plans.
- Simple ingredients: Onion, cheese, and basic seasonings.
Key element — thin, even onion slices
Slice the onions into even ½-inch thick rounds so they cook at the same rate. Thicker slices stay too firm; thinner ones can burn before the cheese melts properly.
Ingredients
Onion rings
- 2 large yellow or sweet onions
- 1½–2 cups shredded mozzarella or a mozzarella–cheddar blend
- ¼–⅓ cup grated Parmesan cheese
- 1–2 Tbsp olive oil or melted butter
- ½ tsp garlic powder
- ½ tsp Italian seasoning or dried oregano
- Salt and black pepper to taste
- Optional: pinch of red pepper flakes or smoked paprika
Optional protein boost
- 2–3 Tbsp unflavored or mozzarella-flavored protein powder mixed with the cheese
To serve
- Fresh parsley or chives
- Optional: sugar-free ranch, spicy mayo, or marinara for dipping
Swaps
- Cheese: Use all mozzarella for maximum stretch or add cheddar for sharper flavor.
- Dairy-free: Use a good melting dairy-free cheese alternative.
- Spicier: Add cayenne or extra red pepper flakes to the seasoning.
- Air-fryer: Works very well for extra crisp edges.
Instructions
| 1 | Prep the onions. Preheat oven to 400°F (200°C). Peel the onions and slice into ½-inch thick rounds. Carefully separate the rings, keeping larger ones for stacking. Pat dry with paper towels. |
| 2 | Season. Place the onion rings on a parchment-lined baking sheet. Lightly brush or drizzle with oil or melted butter. Sprinkle with garlic powder, Italian seasoning, salt, pepper, and optional red pepper flakes. |
| 3 | Add the cheese. Sprinkle the shredded mozzarella (and protein powder if using) generously over and between the onion rings. Top with grated Parmesan. Stack a few rings if desired for a taller presentation. |
| 4 | Bake. Bake 18–22 minutes until the cheese is fully melted, bubbly, and golden in spots and the onion edges are lightly caramelized. For extra browning, broil the last 1–2 minutes while watching closely. |
| 5 | Serve. Let cool 1–2 minutes so the cheese sets slightly. Garnish with fresh parsley or chives and serve hot with optional dipping sauce. |
Pro tips
- Pat the onion slices dry so the cheese sticks better and the edges crisp.
- Use a good melting mozzarella for the best stretch and golden color.
- Don’t overcrowd the pan — give the rings space so they roast instead of steam.
- For crispier results, air-fry at 375–400°F for 10–14 minutes, checking halfway.
- These are best eaten fresh while the cheese is still stretchy.
Nutrition
| Nutrient | Per serving (1/2–1/3) |
|---|---|
| Calories | 320 |
| Protein | 22g |
| Net carbohydrates | 8g |
| Total carbohydrates | 11g |
| Fiber | 3g |
| Total fat | 22g |
| Sodium | 480mg |
Estimates based on mozzarella, Parmesan, and yellow onions. Exact numbers vary with cheese amount and onion size.
Variations
Extra cheesy
Add a second layer of mozzarella or mix in a little cream cheese for even more melt.
Spicy version
Add cayenne, chili powder, or a drizzle of hot sauce after baking.
Garlic-parmesan
Increase the garlic powder and finish with extra grated Parmesan and parsley.
Air-fryer
Cook at 375–400°F for 10–14 minutes, shaking or flipping halfway for even browning.
Storage
| Method | Time | Notes |
|---|---|---|
| Refrigerator | Up to 2 days | Best reheated in oven or air-fryer to re-crisp |
| Freezer | Not ideal | Texture softens; best enjoyed fresh |
| Reheating | — | Oven or air-fryer keeps the edges crisp better than the microwave |
FAQ
Test your knowledge
5 quick questions about these cheesy onion rings
1. Protein per serving?
2. Net carbs per serving?
3. What helps the onion rings crisp up?
4. About how long do these take?
5. Best way to reheat leftovers?
