Put the quinoa in a medium saucepan with 2 cups water and 1/4 teaspoon of the salt. Set the pan over high heat and bring the water to a boil.

Cover the saucepan, turn the heat to low, and cook the quinoa for 15 minutes. The water should be absorbed and the grains should look tender.

Set a large skillet over medium heat and add 2 tablespoons of the olive oil.

Add the sliced fennel and onion to the skillet. Stir to coat them in the oil.

Season the fennel and onion with another 1/2 teaspoon salt and the black pepper. Cook for 8 minutes, stirring every minute or two, until the vegetables soften and start to brown at the edges.

Add the garlic and red pepper flakes to the skillet. Cook for about 30 seconds, stirring, until the garlic smells fragrant.

Pour the vegetable broth into the skillet and add half of the lemon zest. Cover the skillet, lower the heat to medium-low, and cook for 6 minutes, until the fennel is very tender.

Uncover the skillet and add the butter beans. Spoon in about 1 tablespoon of the lemon juice and stir gently so the beans stay mostly whole.

Cook the bean mixture for 3 to 4 minutes, uncovered, until the beans are hot and the broth has reduced slightly into a light sauce. Turn off the heat.

Stir 2 tablespoons of the parsley into the skillet. Taste the bean mixture and add more salt or pepper if needed.

When the quinoa is done, take the saucepan off the heat and let it stand, covered, for 5 minutes.

Add the remaining 1 tablespoon olive oil to the saucepan and fluff the quinoa with a fork so the grains separate.