Bring a large pot of salted water to boil. Add the broccoli and cook for about 2 minutes, until it is slightly softened but still crisp. Use a slotted spoon to transfer the broccoli to a colander. Rinse with cold water to stop the cooking and retain the bright green color. Place the broccoli on a kitchen towel, in a single layer, to dry.

Bring the same pot of water back to a boil, and add the green beans. Cook for about 2 minutes, until the green beans are softened but still crisp. Drain the green beans in a colander and rinse with cold water. Place the green beans on another kitchen towel. 

Pat the green beans and broccoli dry with kitchen or paper towels. Chop the broccoli into small bits, about 1/2-inch. Chop the green beans into small bits, about ¼-inch.

Warm the olive oil in a large skillet over medium heat. Add the garlic and red pepper flakes, and cook for 1 minute, until the garlic is faintly golden. Add the chopped broccoli, chopped green beans, lemon zest, and 1 teaspoon kosher salt. Add several grinds of black pepper and cook, stirring for 3 to 4 more minutes, until the veggies are well-seasoned and slightly more tender.

Place the cooked farro in a large bowl and stir in the vegetables and all the oil and garlic from the skillet. Stir in the cheese and walnuts, then add the lemon juice and more salt and pepper to taste.