Preparation Bring broth to boil in large pot. Add asparagus; cook until crisp-tender, about 4 minutes. Using tongs, transfer asparagus to large bowl of ice water. Reserve 1 cup broth in small bowl. Drain asparagus; pat dry. (Can be made 1 day ahead. Wrap asparagus in paper towels. Seal in plastic bag. Cover broth. Chill asparagus and broth.) Heat 1 tablespoon oil in medium nonstick skillet over medium heat. Add 1 cup green onions, shallots and sugar. Sauté until onions and shallots are tender, about 5 minutes. Add garlic; sauté 2 minutes. Stir in reserved 1 cup broth, 1 tablespoon oil, mustard, lemon juice, thyme and lemon peel. Simmer until slightly thickened and liquid is reduced to 1 1/4 cups, about 5 minutes. Season with salt and pepper. Cool to room temperature. Arrange asparagus on platter. Spoon sauce over. Sprinkle with remaining 1/4 cup green onions and bell peppers.
Preparation Bring broth to boil in large pot. Add asparagus; cook until crisp-tender, about 4 minutes. Using tongs, transfer asparagus to large bowl of ice water. Reserve 1 cup broth in small bowl. Drain asparagus; pat dry. (Can be made 1 day ahead. Wrap asparagus in paper towels. Seal in plastic bag. Cover broth. Chill asparagus and broth.) Heat 1 tablespoon oil in medium nonstick skillet over medium heat. Add 1 cup green onions, shallots and sugar. Sauté until onions and shallots are tender, about 5 minutes. Add garlic; sauté 2 minutes. Stir in reserved 1 cup broth, 1 tablespoon oil, mustard, lemon juice, thyme and lemon peel. Simmer until slightly thickened and liquid is reduced to 1 1/4 cups, about 5 minutes. Season with salt and pepper. Cool to room temperature. Arrange asparagus on platter. Spoon sauce over. Sprinkle with remaining 1/4 cup green onions and bell peppers.