Fill a medium pot with water, add a pinch of salt, and bring to a rolling boil. Prepare a bowl of ice water nearby.
Shell the peas if needed, then add them to the boiling water and cook until just tender, about 30 seconds to 1 minute. The peas should turn bright green and make a slight bubbling sound.
Using a slotted spoon, quickly transfer the peas into the ice water to stop the cooking process and preserve their vibrant color. Let them sit for a few minutes until completely cooled.
While the peas cool, zest and juice the lemon into a small bowl. Add the olive oil, chopped herbs, salt, and pepper, then whisk until emulsified and fragrant.
Drain the cooled peas from the ice water and pat them dry gently. Place the peas in a large mixing bowl.
Pour the lemon dressing over the peas and gently toss to coat evenly. Taste and adjust seasoning with more salt, pepper, or lemon juice if needed.
Add the thinly sliced red onion, chopped herbs, and optional crumbled cheese to the salad. Toss gently to combine everything without breaking the peas.
Transfer the salad to a serving dish, garnishing with extra herbs or cheese if desired. Serve immediately for the freshest, crispest texture.