Step 1: Cook Your Noodles. Bring a large pot of salted water to a rolling boil. Add your chosen pasta (linguine or spaghetti works wonderfully here) and cook according to package directions until al dente. Drain, reserving about 1 cup of pasta water, and set aside.
Step 2: Prepare Green Onions and Garlic. Wash and trim the green onions. Separate the white and light green parts from the dark green tops. Finely slice the white and light green parts, and thinly slice the dark green tops for garnish. Mince the garlic cloves.
Step 3: Sear the Chicken. Pat the chicken breasts dry with paper towels. Season generously with salt and black pepper. In a large skillet or Dutch oven, heat olive oil over medium-high heat. Add the chicken and sear for 4-5 minutes per side, until golden brown and cooked through. Remove the chicken from the pan and set aside on a plate.
Step 4: Sauté Aromatics. Reduce heat to medium. Add the sliced white and light green parts of the green onions and the minced garlic to the same pan. Sauté for 2-3 minutes until fragrant, scraping up any browned bits from the bottom of the pan.
Step 5: Build the Sauce. Pour in the chicken broth and soy sauce, stirring well. Bring to a gentle simmer. In a small bowl, whisk together the heavy cream and cornstarch until smooth. Slowly pour the cream mixture into the simmering sauce, stirring constantly until the sauce thickens to your desired consistency. If it's too thick, add a splash of reserved pasta water.
Step 6: Combine and Finish. Return the seared chicken to the skillet, nestling it into the sauce. If you prefer, slice the chicken into strips or dice it before returning to the pan. Add the drained noodles to the skillet, tossing gently to coat everything evenly in the creamy sauce.
Step 7: Garnish and Serve. Remove from heat. Taste and adjust seasoning if needed. Garnish generously with the reserved fresh dark green onion tops. Serve immediately and enjoy!