Preheat oven to 375°F. Cut the tops off of the garlic bulbs and wrap each loosely with aluminum foil, leaving the top open slightly (like a chimney). Drizzle 2 tablespoons of extra virgin olive oil into each foil opening. Place onto a baking sheet and roast for 15-20 minutes or until garlic is golden brown. Remove from the oven and let cool to room temperature. Once cooled, remove the individual garlic cloves and set aside.
Using paper towels, gently pat dry the scallops. Once dry, season with salt and pepper. Heat extra virgin olive oil in a large skillet over medium-high heat and sear scallops. Cook for 1-2 minutes or until scallops are tender. Remove from the pan using a slotted spoon and set aside.
Reduce heat to medium and whisk in butter. Once butter is melted, sift in flour and whisk, creating a roux. Whisk in broth and bring to a simmer. Once simmering, whisk in roasted garlic cloves.
Stir in cooked linguine and arugula. Once arugula has wilted (1-2 minutes), stir in cooked scallops. Season to taste with salt and pepper before serving.