1. Cook tortellini as label directs; drain, return to saucepot and cover. 2. In large nonstick skillet, heat oil over medium-high heat. Sprinkle salmon with ½ teaspoon salt and ¼ teaspoon pepper; add to skillet and cook 10 minutes or until internal temperature reaches 145°, turning once. 3. In a separate large skillet, melt butter over medium-high heat. Add onion; cook 5 minutes or until tender, stirring occasionally. Add garlic; cook 30 seconds or until fragrant, stirring frequently. Whisk in flour; cook 2 minutes, whisking constantly. Whisk in milk; heat to a simmer. Reduce heat to medium-low; simmer 5 minutes or until thickened, whisking occasionally. Stir in spinach, tomatoes, lemon juice, tortellini and remaining ½ teaspoon each salt and pepper; cook 2 minutes or until heated through and spinach is wilted, stirring occasionally. Makes about 5 cups. 4. Serve tortellini topped with salmon.