French Spring Vegetable Stew (Estouffade Printanière)

Ingredients

• 1⁄4 cup extra-virgin olive oil
• 1 large onion, finely diced
• Kosher salt and freshly ground black pepper
• 12 small carrots, peeled
• 6 small artichokes, trimmed and cut into quarters
• 1 sprig thyme
• 2 cups vegetable broth or water
• 12 baby turnips, peeled and halved
• 2 medium leeks, in 1/2-inch slices, both white and tender green parts
• 1 cup blanced and peeled fava beans
• 1 cup shelled tender peas
• 12 stalks fat green asparagus, peeled, in 1-inch pieces
• 1⁄2 tsp. lemon zest
• 2 tbsp. chopped chervil
• 2 tbsp. chopped parsley