Preheat the oven to 375°F
Combine the olive oil, lemon juice, thyme, garlic, salt, and pepper in a medium nonreactive saucepan. Mix well and set aside while preparing the artichokes.
Snap outer leaves from an artichoke. Cut off the top half, and then use a paring knife to trim down to the heart, rubbing cut surfaces with the lemon half as you work to avoid discoloration. Cut the heart in half and scrape out the choke with a spoon. Cut each piece in half again.
As each artichoke heart quarter is completed, immediately turn it in the marinade to coat completely. When all the artichokes are trimmed, put the pan over high heat and bring to a boil. Pour the artichokes and marinade into a baking dish (or cook them in the saucepan if it is ovenproof), cover with foil, and cook until the artichokes are tender when pierced with a fork, about 45 minutes. Remove from the oven and let cool in the cooking liquid.
Cook fettuccine according to package directions. While pasta is cooking, heat olive oil in a large skillet over medium heat. Add garlic. When garlic is golden, add the oregano and broth. Bring to a simmer, stir in the spinach to wilt. Add the artichokes. Drain the pasta and place in a serving bowl. Pour over the artichoke mixture and toss with the parsley and butter and season with salt and pepper. Sprinkle with Parmesan and serve.