You can make this salad with asparagus, snap peas or English peas or some of each.
Soak 1 C. cannellini or other large white bean in water overnight. Drain and cook in salted water until just tender. (Or drain and rinse 2 cans of beans).
Trim 1 spring onion, then slice lengthwise. Thinly slice the entire onion, white and green parts. Toss in a large bowl with the juice of 1 lemon or 3 T. red or white wine vinegar plus salt and pepper.
Let the onions marinate for 10 minutes, then add the beans to the bowl along with 1 T. stoneground mustard and 4 T. olive oil. Toss well to combine.
Bring a large pot of water to a boil. Snap the bases off 1 bunch of asparagus OR trim 2 C. snap peas OR shell 1 lb. of English peas.
Prepare a cold-water bath in a large bowl.
When the water comes to a boil, add the vegetables. When the water returns to a boil, immediately drain the vegetables and then drop them into the bath. Drain and allow to dry.
Toss the vegetables with the beans and onions.
Wash 4 C. arugula leaves. Spin dry.
Toss the greens with the beans. Top with crumbled goat or feta cheese. Want to use even more greens? Serve the salad on a bed of Lettuce.