In a large dutch oven or pot, heat oil over medium-high heat on the stove top. Add onion, carrots and celery to dutch oven. Cook and stir for 4-5 minutes, or until the onion begins to turn golden brown.: The pan should sound slightly alive with a soft shimmer as the olive oil warms, not a harsh smoke. You want the oil to coat the surface and feel fluid, which helps the aromatics release sugars quickly. When the oil is ready, it will slightly ripple and the first bit of minced onion will sizzle on contact. This step builds the flavor base, so take your time to avoid burning, as scorched oil creates bitter notes. A common mistake is using too high heat, which browns the aromatics too fast and leaves them raw inside, so keep the heat steady.
Add garlic, parsley and thyme to dutch oven, cook for 1 minutes.: You will hear a lively sizzle as the diced vegetables hit the oil, and the scent will turn sweeter within a minute or two. Stir to coat every piece and spread them into an even layer so they cook uniformly. As the vegetables soften they release moisture and a gentle caramel aroma develops around the edges, a key indicator you are developing depth. If the pan looks too dry, add a splash of broth rather than cranking the heat, because rushing this step can produce bitter, overbrowned bits.
Add the salt and pepper, broth, chicken breasts and rice to dutch oven. Stir to combine. Bring to a boil over medium-high heat.: Listen for a consistent gentle sizzle and watch the onion shift from translucent to edged with gold, which signals the sweet compounds are emerging. The carrots and celery should begin to yield, with the carrots starting to soften and the celery losing its raw crunch. Stir periodically to prevent sticking and to expose all pieces to the hot surface. Rushing or leaving the pan unattended often results in uneven browning or burning, which will add harsh flavors to your finished soup.
Reduce heat to simmer, cover and cook for 18-20 minutes, stirring through cooking time. The rice and vegetables should be tender and the internal temperature of the chicken breasts should be 165 degrees Fahrenheit.: When you introduce the minced garlic and dried herbs, the aroma will lift and become herbaceous quickly, but it only needs a brief minute to mellow the garlic's raw edge. Stir constantly so the garlic does not cling to the hot pan and burn, which would introduce bitterness. This brief burst intensifies the aromatics and integrates the herb flavors, creating a fragrant layer that the broth will amplify. A frequent slip here is overcooking the garlic, so watch closely.
Remove chicken from pot and shred. Add back to the pot and stir in evaporated milk.: As you add the seasoning and pour in the 6 cups of low sodium chicken broth , you will see steam rise and the pot come to life. Nestle the raw chicken breasts into the liquid and scatter the uncooked rice so it can absorb heat evenly. Stir gently to distribute seasonings and to ensure the grains are not clumped. This step transforms the pot into a unified cooking environment, where starch from the rice will thicken the broth and the chicken will poach slowly to keep juices intact. Avoid vigorous stirring that could break up the rice too soon.
Stir to combine. Bring to a boil over medium-high heat: As you increase heat toward a boil, watch for steady bubbling across the surface and a warming aromatic lift. The moment the liquid has consistent rolling bubbles, reduce the heat so the cook continues gently. A full, aggressive boil can agitate the rice and make it release too much starch quickly, leading to a gluey texture, so moderation is crucial. If you see very vigorous turbulence, lower the flame to keep things calm.
Reduce heat to simmer, cover and cook for 18 to 20 minutes, stirring through cooking time: Lowering to a simmer creates a gentle, steady movement in the pot, with small bubbles rising and occasional soft bubbling at the edges. The soft percussion of those bubbles tells you the rice is hydrating and the vegetables are tenderizing. Stirring occasionally keeps the rice from clumping and ensures even cooking. After about 18 minutes the grains should be plump and the vegetables yielding, while the chicken will reach a safe internal temperature. A classic error is under simmering which leaves rice underdone, or boiling too hard which overcooks it.
The rice and vegetables should be tender and the internal temperature of the chicken breasts should be 165 degrees Fahrenheit: Check by probing the thickest part of the chicken with an instant read thermometer, looking for 165 degrees Fahrenheit, and taste a bit of the rice for tenderness. Proper doneness yields juicy, shreddable chicken , and rice that is soft but intact. If the temperature is low, return to a gentle simmer rather than increasing heat aggressively, which can dry the meat.
Remove chicken from pot and shred: Use two forks or tongs to lift the breasts out; they should pull apart with little resistance and produce moist, tender shreds. The texture should be fibrous yet soft, and the act of shredding releases additional savory juices that you will return to the pot. If the meat resists shredding, it likely needs a few more minutes back in the simmering broth, as undercooked chicken will be rubbery rather than tender.
Add back to the pot and stir in evaporated milk: When you fold the shredded chicken back into the simmering soup, the pot will smell rounded and full. Stirring in the evaporated milk gently warms it so it blends into a silky finish, turning the broth slightly opaque and rich. This step should be done off high heat to avoid curdling; a low gentle warmth is perfect. Overheating the milk can cause texture issues, so keep it calm and stir steadily until everything is integrated and heated through.