1. Heat a large heavy pot or Dutch oven over medium heat. Add the olive oil and butter and let the butter melt and foam slightly.

2. Stir in the diced onion, carrots, and celery with a pinch of salt. Cook, stirring occasionally, until the vegetables are softened and lightly golden around the edges, about 6 to 8 minutes.

3. Add the minced garlic and cook just until fragrant, about 30 seconds, stirring constantly so it doesn’t burn.

4. Sprinkle the flour evenly over the vegetables and stir to coat them in the fat, forming a thick paste. Cook this roux for 1 to 2 minutes to remove the raw flour taste.

5. Slowly pour in the chicken broth while whisking or stirring constantly to avoid lumps. Add the milk or half and half and continue stirring until the mixture is smooth.

6. Stir in the salt, black pepper, dried thyme, and bay leaf. Bring the mixture to a gentle simmer. It should begin to thicken into a creamy gravy.

7. Add the shredded cooked chicken to the pot, stirring to distribute it evenly. Let it simmer for 3 to 5 minutes so the chicken warms through and absorbs the flavors.

8. Stir in the frozen peas and simmer for another 2 to 3 minutes, just until they are bright green and heated through. Taste and adjust the seasoning with more salt or pepper if needed.

9. While the gravy simmers, open the can of refrigerated buttermilk biscuits. Cut each biscuit into quarters to make bite size dumplings. Lightly dust any sticky edges with a little flour if they stick together.

10. Reduce the heat so the gravy is gently bubbling, not at a rolling boil. Carefully place the biscuit pieces on top of the gravy in a single layer, spacing them slightly apart. Do not stir.

11. Cover the pot with a tight fitting lid and let the dumplings steam in the gravy for about 15 minutes, until they are puffed and cooked through in the center. Gently split one dumpling open to check for doneness; it should not look doughy inside.

12. Remove the bay leaf. If desired, stir in the lemon juice to brighten the flavors. The gravy should be thick, creamy, and full of chicken and vegetables.

13. Sprinkle the chopped fresh parsley over the top and add a few extra cracks of black pepper. Ladle the chicken, veggies, and dumplings into warm bowls and serve immediately.