Remove broccoli from the freezer to begin thawing so it’s easy to chop. Cut chicken breasts in half widthwise to make 4 thinner filets. Use a meat mallet/frying pan/your fist to give each piece a quick pound (Don’t flatten chicken; we just want all the pieces fairly even). Season both sides. (I add 1/4 teaspoon salt and pepper per side and 1/2 teaspoon garlic powder and Italian seasoning per side.)
Add 2 tbsp olive oil to a large, wide, heavy-bottomed pot. Once the oil is hot, add the seasoned chicken pieces in one layer. Cook about 3–4 minutes per side or until chicken is cooked through (registers 160°F/juices run clear). Remove to a plate, tent with foil, and rest for about 5 minutes before thinly slicing, dicing, or shredding with 2 forks.
Meanwhile, back to the pot (don’t rinse it out!), reduce heat to medium and add in remaining 1 tbsp oil plus 1 tbsp butter. Once butter is melted, add onion, celery, and carrot. Season to taste (I add 3/4 tsp salt and 1/2 tsp pepper). Sauté, stirring frequently, scraping up the browned bits left by the chicken, until very tender, 6–8 minutes. (These veggies won’t get much more tender, so take time here.)
Add in minced garlic, chicken bouillon, and remaining 1 tsp Italian seasoning. Stir for 30 seconds.
Add remaining 4 tablespoons butter. Stir until melted. Sprinkle the flour evenly over everything. Cook, stirring constantly, for 1 minute. Gradually add in chicken stock, stirring until smooth, really scraping the bottom of the pot. Add the milk. Increase heat to high and bring to a boil. Stir frequently (and continue to scrape the bottom) to keep the base from sticking. Once boiling, reduce heat to a simmer. Add frozen broccoli, frozen peas, and frozen corn. Cook 2–4 minutes longer or until veggies are tender and warmed through.
Once veggies are tender, turn off the heat. Add cheese, a handful at a time, and gently stir through until melted. Mix in the heavy cream. Finally, add the chicken (along with any juices left behind). Stir through just to rewarm. Taste soup and adjust seasoning to preference.
Serve warm with freshly chopped parsley and hearty warm bread!
Video
Notes
Note 1: Use a food processor to quickly chop equal amounts of onion, carrot, and celery, or you can buy this “mirepoix” mix (already prepped onion, celery, carrots) in the produce section or frozen vegetable section of the store.Note 2: Use sharp or extra-sharp Cheddar (a richer flavor). Shred the cheese fresh; pre-shredded packaged cheese will give the soup a powdery texture and won’t melt as nicely. You can use a food processor to quickly shred cheese! Gently pack cheese into measuring cups to get the right amount.Storage: Store in an airtight container in the fridge for up to 4 days. Reheat on the stove over low heat, stirring often. Freeze for up to 3 months and thaw in the fridge before reheating.