Simple sauteed mushrooms make this elegant hors d'oeuvre from chef Pierre Schaedelin a hearty, satisfying treat. Also Try: Open-Faced Baguette with Cured Salmon and Sauce TartareOpen-Faced Baguette with Fig Marmalade and Blue CheeseOpen-Faced Baguette with Prosciutto and Green Olive Tapenade
Preheat broiler. Slice baguette in half lengthwise and place on a baking sheet cut up; spread cut sides with herbed butter spread. Transfer baking sheet to broiler and broil until tops are toasted, 2 to 3 minutes. Turn and continue broiling until bottoms are toasted, 2 to 3 minutes. Let bread cool to room temperature.
Meanwhile, fill a large bowl with water and add lemon juice; set aside. Remove leaves from artichokes and halve lengthwise; transfer to bowl of acidulated water and set aside.
Heat olive oil in a medium skillet over medium-high heat. Add sliced mushrooms and season with salt and pepper; cook, stirring, until browned, 2 to 3 minutes. Remove from heat and set aside.
Peel and core soaked artichokes and transfer to a medium saucepan; cover with acidulated water and bring to a boil over high heat; cook for 8 minutes. Drain. Rinse artichokes and pat dry. Thickly slice artichokes lengthwise and drizzle with olive oil; set aside.
Top cooled bread with duxelles, dividing evenly between each half. Top duxelles with artichoke slices, followed by sauteed mushrooms; serve.