This recipe is an adaptation of the enticing stew served at Nicolás Jimenez's Restaurante Túbal, in Navarra. Jimenez updates the dish by reducing the cooking time, which keeps the vegetable flavors bright. He also lightens the recipe by adding less flour to the sauce of olive oil, garlic and ham.
1 pound fingerling potatoes, scrubbed but not peeled
1 cardoon rib or celery rib, peeled and cut into 1-inch lengths
3/4 pound green beans, halved lengthwise
6 tablespoons extra-virgin olive oil
3 garlic cloves, thinly sliced
4 ounces thinly sliced serrano ham, cut into 1-inch pieces
1 tablespoon all-purpose flour
Fill a large bowl with water and squeeze the lemon half into it. Working with 1 artichoke at a time and using a sharp knife, cut off the top two-thirds of the leaves. Pull off the outer leaves until you reach the tender yellow leaves. Scrape out the choke with a melon baller or a spoon. Trim the base and peel the stem, then thickly slice the heart and add it to the lemon water. Repeat with the remaining artichokes.
In a large saucepan of boiling salted water, cook the spinach just until wilted, about 1 minute. Using a slotted spoon, transfer the spinach to a colander. Let cool slightly, then squeeze dry and chop finely. Transfer to a small bowl.
Meanwhile, add the potatoes to the boiling water and cook until tender, about 15 minutes. Using a slotted spoon, transfer the potatoes to a large bowl.
Add the cardoon or celery to the boiling water and cook until tender, about 8 minutes for cardoon, 3 minutes for celery. Using the slotted spoon, add the celery to the potatoes. Cook the beans in the boiling water until just tender, 2 minutes; using the slotted spoon, add the beans to the potatoes.
Drain the artichoke slices and add them to the boiling water. Cook until tender, about 8 minutes. Using the slotted spoon, add the artichokes to the potatoes; reserve 1 1/4 cups of the cooking water.
In a large skillet, heat 2 tablespoons of the oil. Add the garlic and cook over moderately high heat until softened and beginning to brown, about 1 minute. Add the ham and stir until the ham and garlic are lightly browned and crisp, about 2 minutes.
Add the blanched vegetables and half of the spinach to the skillet and cook, stirring, until warm. Transfer to a shallow bowl and season with salt if necessary. Add the remaining 1/4 cup of oil to the skillet, stir in the flour and cook until sizzling. Add the reserved 1 1/4 cups of cooking water and the remaining spinach and cook, stirring, until the sauce is creamy, about 3 minutes. Drizzle on the vegetables and serve.