Wash asparagus; snap off tough stem ends. In large skillet or Dutch oven, bring 1 inch of lightly salted water to a boil. Arrange asparagus spears evenly in skillet. Cover; cook 4 to 5 minutes or until asparagus is crisp-tender. Drain.
Meanwhile, in small saucepan, mix butter and walnuts. Cook over low heat until butter browns and walnuts are toasted, watching carefully to prevent butter from burning. Stir in oil and salt.
Arrange hot asparagus on large serving platter. Top with walnut butter.