Season the scallops with the grated lemon zest, i tablespoon thyme leaves and parsley. Cover and refrigerate for 4 hours or overnight.
Remove the scallops from the refrigerator 15 minutes before cooking.
Heat a large sauté pan over high heat for 2 minutes. Season the scallops with salt and pepper. Add 2 tablespoons of extra virgin olive oil to the pan and wait for 1 minute.
Add the scallops to the pan, making sure they are not touching (if the pan is not large enough, do in two batches). Sear the scallops for 1 1/2 minutes per side. Scallops should have a 1/4 inch golden crust on each side and still translucent in the center. Transfer to a rack and cover with foil.
Heat a clean large sauté pan over medium heat for 1 minute. Add 2 tablespoons of extra virgin olive, wait for a moment for the oil to warm up. Add the spring onion slices, asparagus, 1/2 teaspoon salt, a few grinds of pepper and the 1 teaspoon of thyme leaves. Sauté for about 3 minutes, stirring until onions are translucent. Add 3 tablespoons of butter and 1 tablespoon of water. . Stirring until liquid comes to a simmer. Remove from heat and add a squeeze of lemon juice.