In a Dutch oven, heat the vegetable oil over medium-high heat.
Add the chicken and cook until browned on both sides.
Remove from the pot and set aside.
Add onion, celery and carrot, saute until tender crisp, we want some caramelization here
Add garlic and stir until fragrant, ~ 60 sec
Drop the heat to medium low, add the butter and foam out
Sift in the flour and stir for 3 minutes, we want a smooth paste, coating the veggies
Add back the chicken and and juices, store to coat
Add in the chicken stock in small doses whilst stirring to avoid lumps
Add the thyme, bay leaves and bring to a simmer
When simmering add the peas, cover and cook for 15 minutes
Taste, season and balance flavor