Peas fresh from their pod and served on a bed of radicchio.
Place radicchio in a serving bowl.
In a small saucepan, bring peas, water, vinegar, oil, sugar, salt, and pepper to a simmer over medium heat. Cover, and cook until peas are just tender, about 6 minutes for fresh peas and 2 minutes for frozen. Pour hot pea mixture over radicchio, and toss. Serve immediately.