1. Zest the lemons and lay out the zest to dry it slightly, about 30 minutes.
2. Preheat the oven to 230°C.
3. Mix the lemon zest with the salt in a small bowl and set aside. Cut 2 of the lemons in half and set aside.
4. Drizzle the asparagus with olive oil on a baking sheet and toss to coat. Roast until the asparagus have some blackened bits, about 10 minutes. Sprinkle the peas all over the asparagus, toss and squeeze on the juice of the 2 cut lemons. Return to the oven for 3 minutes.
5. Serve on a big platter and sprinkle with the lemon salt, basil and parsley before serving.