0 Bake the puff pastry according to the package directions. Once baked, cut it into 4 equal portions.
1 In a large skillet over medium heat, melt the butter. Add the diced onion and cook until softened and lightly browned.
2 Whisk the cornstarch with 60 ml of the cold chicken stock until smooth.
3 Add the remaining 240 ml chicken stock, fully cooked shredded chicken, milk, frozen vegetables, rosemary, salt, half & half, garlic, black pepper, and paprika. Bring to a gentle simmer over medium-low heat and cook until the vegetables are heated through.
4 Stir the slurry again, then pour it in gradually while stirring. Simmer until the filling thickens, then remove and discard the rosemary sprigs.
5 Divide the filling among 4 bowls or ramekins and top each with one pastry portion.
6 Enjoy!