Prep the Ingredients: Cut the chicken into 1-inch cubes and season with salt and pepper. Mince the garlic and slice the mushrooms and green onions.

Cook the Chicken: Heat the olive oil and butter in a large pot or Dutch oven over medium-high heat. Add the chicken pieces and cook until golden brown and cooked through, about 5-7 minutes. Remove the chicken from the pot and set aside.

Sauté the Aromatics: In the same pot, add the sliced mushrooms and cook until they've released their moisture and started to brown. Add the minced garlic and cook for another minute until fragrant.

Build the Creamy Broth: Pour in the chicken broth and soy sauce, scraping up any browned bits from the bottom of the pot. Bring to a simmer, then reduce the heat to low and stir in the heavy cream.

Cook the Noodles: While the broth is simmering, cook the ramen noodles in a separate pot of boiling water according to package directions. Drain well.

Combine and Serve: Return the cooked chicken to the pot with the creamy broth. Add the fresh spinach and stir until it has just wilted. Divide the cooked noodles among serving bowls, then ladle the creamy garlic chicken broth over the top. Garnish generously with sliced green onions and a sprinkle of sesame seeds.