Heat olive oil in a Dutch oven and saute onion. When it starts to become translucent, add carrots and potatoes and let cook a minute or two.
Add broth, herbs and salt to taste. Bring to boil, then turn down heat and let simmer until carrots and potatoes are soft. Remove bay leaves.
Melt the butter in a frying pan. Add the flour and stir to make a roux. Gradually add some broth from Dutch oven and stir until a thick liquid forms. When you have a decent amount of liquid, add it back into the Dutch oven and stir in chicken. Taste and adjust seasonings as needed.
Heat your regular oven to 425 degrees. Drop biscuit topping onto chicken mixture. Put the Dutch oven into your regular oven and bake until biscuit topping is done, maybe about 30 minutes. The topping will be lightly browned.
Combine dry ingredients. Stir in butter and milk. Drop in spoonfuls on top of pot pie.