1. In a small blender make a slurry by combining milk, flour and cream cheese. Set aside. Place peppers, onions, and garlic in a medium bowl. Season generously with Cajun seasoning, garlic powder and salt.
2. Prepare pasta according to package directions.
3. Heat a large heavy nonstick skillet over medium-high heat; add olive oil to the skillet and reduce to medium; add peppers, onions, and garlic to skillet, sauté 3-4 minutes. Add mushrooms and tomatoes; sprinkle some more Cajun seasoning over top, and sauté 3-4 more minutes or until vegetables are tender. Season with ¼ teaspoon salt, garlic powder and fresh cracked pepper to taste.
4. Reduce heat to medium-low; add vegetable broth and pour in slurry stirring for 2 minutes. Add linguine and toss well to coat. Top with chopped scallions and serve while hot.