In a large, deep skillet, heat the olive oil. Add the garlic, artichokes and crushed red pepper and season lightly with salt. Cook over high heat until the garlic is golden and fragrant, about 3 minutes. Stir in the parsley and lemon juice. Add the pasta and the reserved cooking water to the skillet along with the ricotta and cook, tossing and stirring until the strands are nicely coated, about 2 minutes. Transfer the pasta to bowls and serve, passing the grated cheese at the table.