Cut the stems off the artichokes and snap off the small leaves at the bottom. Cut off the top quarter of each artichoke with a sharp knife. Use scissors to trim off the pointy tips of the remaining leaves.

Simmer the artichokes in a large pot of lightly salted water, covered, over moderate heat until the bases are tender, 20-30 minutes. Transfer them to paper towels and let them drain upside down until cool.

Meanwhile, make the artichoke stuffing by heating 1 cup of the oil in a large skillet over moderate heat until warm. Add the garlic and cook until soft. Stir in the pepper flakes and the bread crumbs and remove the skillet from the heat. Stir in the Parmesan cheese, basil, and thyme and set aside.

Heat the remaining 1/4 cup oil in another large skillet over medium-high heat until hot. Season the shrimp with salt and pepper and sauté for 2 minutes. Add the crabmeat, Sauce Ravigote, and green onions and sauté for 1 minute. Remove the skillet from the heat and stir in 3 tablespoons of the bread crumb mixture. Season the stuffing with salt and pepper.

Preheat the oven to 350°F. Gently pry open each artichoke leaf and pack a spoonful of the stuffing between the leaves. Set the stuffed artichokes in a roasting pan or baking dish and pack their tops with the remaining bread crumb mixture.

Tightly cover the pan with aluminum foil and bake the stuffed artichokes for 35 minutes. Remove the foil and continue baking the artichokes until the stuffing is golden brown, 10-15 minutes more.