Poached Eggs on Artichoke Bottoms with White Truffle Cream and Mushrooms

Name: Poached Eggs on Artichoke Bottoms with White Truffle Cream and Mushrooms
Ingredients: 1 lemon, halved, plus 1 tablespoon fresh lemon juice; 4 large artichokes (10 to 12 ounces each); 1 tablespoon all-purpose flour; 1 tablespoon olive oil; 1 tablespoon kosher salt; 3 ounces small fresh porcino or cremino mushrooms (3), trimmed; 1 1/4 cups heavy cream; 1 tablespoon finely grated Parmigiano-Reggiano; 1/2 teaspoon kosher salt, or to taste; 1/2 teaspoon white truffle oil; 1/4 teaspoon black pepper; 1 teaspoon distilled white vinegar; 4 large eggs; Garnish: finely chopped fresh flat-leaf parsley