1. Start by heating the olive oil in a skillet over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes. Stir in the minced garlic and cook for another minute until fragrant.
2. Transfer the sautéed onion and garlic to your slow cooker. Nestle the chicken breasts on top, then sprinkle with oregano, basil, salt, and pepper.
3. Pour in the chicken broth, milk, and drained diced tomatoes. Give everything a gentle stir to combine the ingredients without disturbing the chicken too much.
4. Cover and cook on low for 4 to 5 hours, or on high for 2 to 3 hours. The chicken should be tender and cooked through.
5. Once the chicken is done, remove it from the slow cooker and shred it with two forks. Return the shredded chicken to the pot.
6. Add the uncooked penne pasta, stirring gently to ensure it’s submerged in the liquid. Cover and cook on high for another 30 to 40 minutes, checking occasionally to make sure the pasta is tender and the sauce hasn’t dried out. Add a splash of broth if needed.
7. When the pasta is perfectly cooked, stir in the mozzarella and Parmesan cheeses until melted and creamy. Taste and adjust seasoning as needed.
8. Serve immediately, garnished with fresh basil or parsley if you like. I love how this final touch adds a bright note that reminds me of my grandmother’s garden in Monterey.

“Slow cooking teaches patience, but the reward is a dish bursting with deep, developed flavors that bring everyone to the table.”