Combine scapes, green onions, walnuts and olive oil in a food processor. Add salt and pepper. Process until desired consistency. Set aside.
Add oil to medium saucepan over medium-high heat. Add shallot, salt, pepper and crushed red pepper and cook until the shallot is browning and translucent. Add couscous and cook until it is just beginning to brown.
Add wine and cook, stirring, until almost evaporated. Add stock and bring up to a boil, reduce heat. Add broccoli and simmer (stirring occasionally) on low heat until the couscous is tender and the liquid has evaporated. Approximately 10 minutes.
Remove from the heat and mix in the pesto and greek yogurt. Adjust salt and pepper to taste. Top with chopped green onion before serving.