Coat shrimp with cajun seasoning, salt, and pepper. Boil pasta, saving some of the water. Melt butter with olive oil, and saute onion, broccoli, and red pepper. Add cream, tomato paste,parsey, water from pasta if needed,sugar, and bring to simmer Add shrimp and cook 3-4 minutes till done. serve sauce over linguini.Serve with lemon wedge on the side.