Preparation Preheat oven to 450°F. Combine onion rings, oil, and salt in medium bowl; toss to coat. Spread onion rings in single layer on rimmed baking sheet. Roast until golden brown, stirring occasionally, about 20 minutes. DO AHEAD Can be made 1 day ahead. Cover and refrigerate. Before using, rewarm in 350°F oven until heated through, about 10 minutes. Bring 3 cups water to boil. Add peas; simmer until tender, about 5 minutes. Drain. Return peas to saucepan. Mix in roasted onion rings, mint, pepper, and sugar. Transfer to bowl and serve.
Preparation Preheat oven to 450°F. Combine onion rings, oil, and salt in medium bowl; toss to coat. Spread onion rings in single layer on rimmed baking sheet. Roast until golden brown, stirring occasionally, about 20 minutes. DO AHEAD Can be made 1 day ahead. Cover and refrigerate. Before using, rewarm in 350°F oven until heated through, about 10 minutes. Bring 3 cups water to boil. Add peas; simmer until tender, about 5 minutes. Drain. Return peas to saucepan. Mix in roasted onion rings, mint, pepper, and sugar. Transfer to bowl and serve.