Add the olive oil to a large soup pot over medium-high heat.
Add the diced chicken and cook until golden brown and cooked through. Remove the chicken from the pot.
Add the butter to the remaining olive oil and melt.
Add the diced onion, carrots, celery, and mushrooms, and stir to combine.
Cook for 10 minutes, until the vegetables have softened, stirring occasionally.
Add the garlic, salt, and pepper, and stir well to combine, cooking 1 more minute.
Add the flour, stirring to combine and cook for 1 minute.
Slowly add the chicken broth, stirring constantly to incorporate with the vegetable mixture.
Add the chicken and peas to the pot, bring the mixture to a boil and simmer for 5 minutes.
Stir in the cream or milk.
Serve with the biscuits and enjoy!