Bring a large pot of salted water to a boil. Cook pasta 3 minutes less than the al dente time on the package; drain.
Meanwhile, heat oil in a large cast-iron or nonstick skillet over medium-high heat. Season scallops with salt and pepper. Cook, turning occasionally, until golden brown and just cooked through, 2 to 4 minutes. Transfer to a plate.
Add garlic and shallot to skillet. Season with salt and pepper. Cook, stirring occasionally, until shallot is just tender, 2 to 3 minutes. Add wine and cook until thickened, 1 to 2 minutes, scraping up any burnt bits. Add stock, butter, and cooked pasta. Cook, tossing, until pasta is al dente and stock is thickened, 2 to 3 minutes. Stir in herbs and scallions. Season with salt and pepper. Serve immediately.