Heat olive oil in a large pot over medium–high heat. Add artichoke hearts and season with salt and pepper. Cook until browned, 5–8 minutes. Add garlic and leeks, cook until garlic starts to brown and leeks are tender, 5–8 minutes.
Add lemon slices and let them soften, a minute or two.
Add white beans and water, bring to a simmer. Add fish sauce, salt, and pepper. Cook until beans taste delicious, 10–15 minutes. Season with salt, pepper, and more fish sauce as needed.
Add asparagus, peas, pea shoots/spring greens, and half of the scallions/alliums. Cook until greens are bright green and tender.
To serve, add lemon juice and remaining alliums. Season with salt, pepper, more lemon juice or fish sauce as desired. Divide among bowls and top with Parmesan, herbs, black pepper, and a drizzle of olive oil.
