Step 1
Bring a large pot of water to a boil over medium-high heat. Add spinach and cook just until wilted, about 45 seconds. Use a slotted spoon or fine sieve to transfer the spinach to a blender. Return the water to a boil and add spaghetti and potatoes. Cook, stirring once or twice, until almost tender, 6 to 7 minutes. Add green beans and cook until tender, 3 to 4 minutes more.