1. Prepare the chicken: Start by cutting your boneless, skinless chicken breasts or thighs into uniform 1-inch pieces. This ensures even cooking. Pat the chicken dry with paper towels; this helps it brown slightly if you choose to sear it first, though it’s optional for this recipe.

2. Saute aromatics (optional but recommended for flavor): In a large skillet over medium heat, warm the olive oil. Add the chopped onion, carrots, and celery. Cook for about 5-7 minutes until the vegetables start to soften. Stir in the minced garlic and cook for another minute until fragrant. This step builds a deeper flavor foundation for your stew. If you’re really short on time, you can skip this and add them directly to the slow cooker, but the sauteing really enhances the taste.

3. Combine ingredients in the slow cooker: Transfer the sauteed vegetables (if you did this step) or the raw vegetables directly into your slow cooker. Add the cut chicken pieces, diced tomatoes (undrained), chicken broth, dried thyme, dried rosemary, salt, and black pepper. Stir everything gently to combine.

4. Set and forget: Cover the slow cooker with its lid. Cook on high for 4-6 hours, or on low for 6-8 hours. The chicken should be tender and easily shreddable with a fork, and the vegetables should be soft.

5. Add frozen vegetables: During the last 30 minutes of cooking, stir in the frozen peas and corn. This ensures they cook through but retain their vibrant color and texture without becoming mushy.

6. Thicken the stew (optional): If you prefer a thicker stew, in a small bowl, whisk together the cornstarch and cold water until smooth to create a slurry. Stir this slurry into the hot stew. Cover and continue to cook for another 15-30 minutes, or until the stew has thickened to your desired consistency.

7. Taste and serve: Taste the stew and adjust seasonings if necessary. Ladle the hot stew into bowls, garnish with fresh chopped parsley, and serve immediately.