Season the chicken breasts with salt and pepper, then place them in a saucepan with the chicken broth and bouillon cube. Bring to a simmer with the lid cracked, and cook for 15 minutes until the chicken is cooked through. While the chicken cooks, dice the onions, carrots, celery, and garlic into uniform 1/4-inch pieces—this ensures even cooking and consistent texture in your filling. Once the chicken is done, remove it to a cutting board and let it cool slightly, then shred it into bite-sized pieces. Reserve the cooking broth in the saucepan for building your sauce base.

In the same saucepan with the reserved broth, melt the butter over medium heat. Add the diced onions, carrots, and celery, and sauté for 5-6 minutes until they begin to soften and the onions become translucent. This creates a flavorful base and develops sweetness in the vegetables. Add the minced garlic and all the dried seasonings (sage, rosemary, thyme, and onion powder), cooking for 1 minute to bloom the spices and release their essential oils. Sprinkle the flour over the vegetables and cook for 2 minutes, stirring constantly to form a paste—this roux will thicken your sauce and create a silky texture. I find that cooking the roux for a full 2 minutes removes any raw flour taste and helps bind the liquid smoothly.

Slowly pour in the reserved chicken broth while whisking constantly to prevent lumps from forming in the sauce. This gradual addition is crucial for achieving a smooth, lump-free filling. Once the broth is fully incorporated, slowly add the half and half while continuing to stir gently—add it in a thin stream rather than all at once, as this helps it blend smoothly with the hot broth without curdling. Add the soy sauce, which adds depth and umami without making the dish taste salty. Let the sauce simmer for 2-3 minutes, stirring occasionally, until it thickens enough to coat the back of a spoon. If it seems too thin, simmer a bit longer; if it's too thick, thin it with a splash of broth. I like to taste and adjust seasoning with additional salt and pepper at this point rather than waiting until the end.

Add the shredded chicken from Step 1 back into the sauce and stir to combine evenly. The chicken will warm through quickly in the hot sauce. Add the frozen peas directly from the freezer and stir to incorporate—they'll thaw from the residual heat of the filling in just a minute or two. Remove the pot from heat once everything is combined and warmed through. Taste and adjust seasonings with additional salt and pepper if needed. If your filling seems thin, let it rest off heat for a couple of minutes as it will continue to thicken slightly as it cools.

Transfer the filling to a 9x13 inch baking dish (or similar size) if your saucepan is not oven-safe. Spoon or spread the prepared buttermilk biscuit dough evenly over the top of the filling, leaving small gaps to allow steam to escape and biscuits to brown. Place the dish in a preheated 425°F oven and bake for 15-18 minutes until the biscuits are golden brown on top. The biscuits should be cooked through and rise above the filling—they'll be slightly crispy on the edges and tender inside. Let the pot pie rest for 5 minutes after removing from the oven before serving, as this allows the filling to set slightly and makes it easier to scoop.