Microwave the cauliflower according to the package directions. Combine the cauilflower and Boursin cheese in a food processor until smooth. Set aside.
Preheat oven to 400 degrees.
Add olive oil to a large saute pan over medium-high heat. Add the onions and the carrots and cook for 5 minutes, stirring often. Add the garlic and continue to cook for one minute. Add the ground turkey, salt and pepper and cook until no longer pink, breaking the meat up with a spoon.
Sprinkle the meat with the flour, stirring until combined. Cook for 2 minutes. Add the chicken broth, tomato paste, Worcestershire sauce, thyme and rosemary. Stir until well combined. Bring the mixture to a boil, then reduce to a simmer and cook until the mixture thickens, about 8-10 minutes,
Add the corn and the peas and mix to combine. Spread the mixture in a 9x9 baking dish. Top with the cauliflower mash, spreading to the edges. Sprinkle top with parsley, if desired.
Bake for 25 minutes until cauliflower mash begins to brown and mixture appears to be bubbling. Remove from oven and let stand for 10 minutes before serving.