To make pasta: In a large bowl, stir flours, eggs and 1/2 teaspoon salt together to make a stiff dough. On a lightly floured surface, knead dough until smooth and not sticky, about 20 times. Cover with plastic wrap and let rest at room temperature 30 minutes. Cut dough in half. Using a pasta machine, process each half according to manufacturer's instructions. Or place half on lightly floured surface (keep remaining dough in plastic wrap) and with a floured rolling pin, roll into a 12-inch square. With a pastry wheel or knife, cut crosswise into 1-inch-wide strips. Sprinkle with flour and layer on a lightly floured jelly-roll pan, using plastic wrap between layers. Repeat with remaining dough. Set aside.

To make sauce: In a 12-inch nonstick skillet, heat 2 tablespoons olive oil over medium-high heat. Add asparagus, 1/4 teaspoon salt, and 1/8 teaspoon white pepper. Cover and cook 2 minutes; then add shallots and garlic. Sauté 2 minutes; remove asparagus to a plate. Set burner on high; heat the remaining tablespoon olive oil in same skillet. Add shrimp and sprinkle with 1/4 teaspoon salt and 1/8 teaspoon pepper. Sauté 1 minute per side, until golden. Add wine, tomatoes, and remaining 1/2 teaspoon salt; simmer until shrimp are just opaque in center. Remove pan from heat; stir in parsley and asparagus.

Meanwhile, in an 8-quart saucepan, cook pappardelle in 6 quarts boiling water. Add 2 teaspoons salt if desired. Gently stir to separate pasta; cook 2 to 3 minutes, until tender but firm. Drain. Do not rinse.

Toss pappardelle with sauce and serve immediately.