Prep the veggies: Dice the onion, slice the carrots and celery, and mince the garlic.
Keep them in evenly sized pieces so they cook at the same rate.
Sauté for extra flavor (optional but worth it): In a skillet, warm olive oil and butter over medium heat. Cook onion, carrots, and celery with a pinch of salt for 5–6 minutes until slightly softened. Add garlic for 30 seconds.
Transfer everything to the slow cooker.
Add the chicken and seasonings: Place chicken on top of the vegetables. Sprinkle with thyme, parsley, a generous pinch of salt, black pepper, and poultry seasoning if using. Add the bay leaf.
Pour in the broth: Add chicken broth to the slow cooker.
Stir gently to combine without burying the seasonings on the chicken too much.
Cook low and slow: Cover and cook on Low for 6–7 hours or High for 3–4 hours, until the chicken is fork-tender.
Shred the chicken: Remove the bay leaf. Transfer chicken to a cutting board and shred with two forks. Return the meat to the slow cooker and stir.
Make it creamy: Whisk the cornstarch with 2 tablespoons cold water to make a slurry, if you want a thicker base.
Stir it into the slow cooker along with the heavy cream or half-and-half.
Add dumplings: Cut biscuit dough into small pieces (about 1-inch). Drop them evenly over the surface of the stew. Gently press them down so they’re just touching the liquid.
Finish cooking: Cover and cook on High for 1–1.5 hours, or until the dumplings are puffed and cooked through in the center.
Avoid lifting the lid too often—steam is key for fluffy dumplings.
Season and serve: Stir in frozen peas and a small squeeze of lemon, if using. Taste and adjust salt and pepper. Ladle into bowls and enjoy warm.