Step 1

Vigorously whisk 6 eggs in a medium bowl until streak-free.→ Here's how to buy the best eggs possible.

Step 2

Add 5 oz. vegetables, ½ cup grains, 1 oz. grated cheese, and 1 Tbsp. herbs; season with salt and pepper. Mix with a rubber spatula to combine.

Step 3

Heat 1 Tbsp. oil in a medium nonstick skillet over medium; swirl skillet to coat with oil.

Step 4

Add egg mixture and cook until edges are set, about 30 seconds.

Step 5

Using spatula, agitate eggs by scraping bottom of skillet in a small circular motion and bringing edges toward center of pan to form large curds, then let mixture sit undisturbed until edges are set again, about 1 minute.

Step 6

Reduce heat to low and continue to cook, tilting skillet and lifting edges up with spatula to allow uncooked egg to flow underneath and around sides, until surface is wet but center is mostly set when you shake the pan, about 5 minutes.

Step 7

Shake skillet to loosen frittata. Place a large plate over skillet and invert frittata onto plate.

Step 8

Heat remaining 1 Tbsp. oil in skillet over medium, swirling to coat. Slide frittata back into skillet; reduce heat to low. Cook until set all the way through, about 3 minutes.

Step 9

Let frittata cool in skillet 5 minutes, then invert onto a cutting board.

Step 10

Season frittata with salt and pepper. Cut into wedges to serve.

Step 11

Do Ahead: Frittata can be made 1 day ahead. Cover and chill. Bring to room temperature before serving.