Place a large dutch oven or pot over medium high heat. Add olive oil. Once hot, add diced chicken breast and season with salt and pepper. Cook for 4-6 minutes until thoroughly cooked and no longer pink. Remove chicken and set aside.

In the same pot, add 1/2 tablespoon olive oil, chopped onion, sliced carrots, diced potatoes, diced cauliflower, and thyme. Saut? until onion softens, then add milk, chicken broth, salt, and pepper. Simmer uncovered for 10 minutes until potatoes are fork tender.

Remove 3 cups of the mixture from the pot and blend until smooth. Transfer puree back to the pot. Stir in cooked chicken and frozen peas. Simmer for an additional 5-10 minutes to thicken. Taste and adjust salt and pepper as needed.