Preheat your oven to 300°F and line a baking sheet with parchment paper. Separate your room-temperature eggs carefully, making sure no yolk gets into the whites—even a tiny bit of yolk will prevent the whites from reaching stiff peaks. I like to use three bowls for this: one for each white, one for the yolks, and one for mixing, so I can separate each egg into its own bowl first before combining whites together. This safety margin prevents ruining the entire batch if one egg breaks.

In a clean, dry bowl, combine the egg whites with the cream of tartar. Using an electric mixer on medium-high speed, beat for 4-5 minutes until stiff peaks form—the whites should look glossy, thick, and hold their shape when you lift the beaters. The cream of tartar helps stabilize the foam and creates a more voluminous, sturdy meringue. Don't underbeat this step; stiff peaks are essential for a light, airy bread.

In a separate bowl, whisk together the egg yolks, Greek yogurt, bagel seasoning, and salt until smooth and well combined. The yogurt adds moisture and richness while keeping this bread keto-friendly. Mix until you have a uniform yellow mixture with no streaks of white.

Pour the yolk mixture from Step 3 into the whipped egg whites from Step 2. Using a rubber spatula, gently fold the mixture together using a slow, deliberate motion—cut down the center, sweep along the bottom, and fold up and over, rotating the bowl as you go. Do this for about 15-20 folds until the mixture is evenly combined but still light and fluffy. I prefer to fold by hand rather than mix because it preserves the air bubbles we worked hard to create, which gives the bread its characteristic light texture.

Spoon the batter onto the prepared baking sheet in 6 even circles, spacing them about 2 inches apart so they bake evenly with good air circulation. Bake in the preheated 300°F oven for 30 minutes, until the bread is set, lightly golden on top, and springs back when gently touched. The low oven temperature ensures the delicate structure cooks through without browning too quickly on the outside.

Remove the bread from the oven and let it cool on the baking sheet for at least 10 minutes before eating or storing. The bread will continue to set as it cools. Serve warm or at room temperature—these are delicious fresh and can be stored in an airtight container in the refrigerator for up to 3 days.