Instructions
Step 1
Position a rack in the center of the oven and preheat to 400°F.
Step 2
Bring a large pot of salted water to a boil. Add the spaghetti and cook according to the package instructions until al dente. Drain the pasta and transfer to a large bowl. Set aside and keep warm.
Step 3
In a medium bowl, toss together the oil, tomatoes, garlic scapes, and onion. Season to taste with salt and black pepper, then spread the vegetables in an even layer on a large rimmed baking sheet. Bake until the tomatoes are just beginning to burst, 12–15 minutes.
Step 4
Remove the vegetables from the oven and add to the bowl of spaghetti. Add the arugula and lemon juice and zest, toss to combine, and serve hot.