Start the skillet: Set a large deep skillet with a lid over medium heat.

Warm the oil: Add the olive oil to the skillet and let it warm for about 30 seconds.

Soften the onion: Add the chopped onion and 1/2 teaspoon of the salt to the skillet. Cook for 4 to 5 minutes, stirring often, until the onion is soft and starting to look translucent.

Toast the farro: Add the farro to the skillet. Stir for 1 minute so the grains are coated in the oil and lightly toasted.

Add the broth: Pour the vegetable broth into the skillet and add 1/4 teaspoon of the black pepper. Raise the heat to medium-high and bring the liquid to a boil.

Simmer until tender: Once the broth is boiling, lower the heat to medium-low and cover the skillet. Cook for 10 to 12 minutes, until the farro is tender and most of the liquid is absorbed.

Check the texture: Uncover the skillet and stir the farro. If the pan looks dry before the farro is tender, add 1/4 cup water and cook for 2 to 3 minutes more.

Add the peas: Add the frozen peas to the skillet. Stir and cook for 2 minutes, until the peas are hot.

Wilt the spinach: Add the spinach to the skillet a handful at a time, stirring after each addition. Cook for 1 to 2 minutes, until the spinach is wilted and mixed through the farro.

Stir in the pesto: Turn off the heat. Stir the pesto, the lemon juice, and about half of the crumbled feta into the skillet until the farro looks glossy and evenly green.

Season the base: Taste the farro and add the remaining 1/4 teaspoon salt if needed. Add a little more black pepper if you want more bite.

Make room for the eggs: Use the back of a spoon to make 4 small wells in the farro mixture. Space them out so each egg has room to sit in the skillet.