Preheat oven to 400°F.
In a large deep skillet, sauté chicken in olive oil over medium heat until browned and juices run clean. About 5-6 minutes. Remove chicken from pan and set aside.
In the same skillet, add butter and onions. Cook onions for 2-3 minutes until soft and translucent.
Add in the garlic and sauté another minute until garlic is fragrant.
Add the chicken and any juices back to the skillet.
Stir in the all purpose flour, thyme, parsley, salt and black pepper. Cook for 1-2 minutes.
Slowly pour in the chicken broth while stirring, followed by the heavy cream.
Add the potatoes and stir to combine. Bring to a boil, reduce heat to low and simmer for 10-12 minutes and until the potatoes are fork tender, stirring occasionally.
While the filling simmers: make the biscuits. In a large mixing bowl, combine the all purpose flour, baking powder, salt, thyme, and parsley.
Add the diced cold butter and cut it into the dry ingredients with a pastry blender or your fingers.
Stir in the cold milk just until combined. Set the dough in the fridge until ready to use.
Once the potatoes are tender, remove filling from heat and stir in bag of mixed vegetables.
If needed, transfer filling to a deep 3 quart casserole dish.
Using a large scoop, add 12 biscuits to the top of the filling. Optional: brush with heavy cream or melted butter for a crispier biscuit.
Bake for 25-30 minutes until biscuits are browned on top and filling is bubbly.