Cook the spaghetti in boiling water until just tender, drain and keep hot.
In a small saucepan, bring 2 cups of water to a boil. Add a pinch of salt and frozen peas. Boil for 2-3 minutes. Drain and set aside.
Heat broth in a small saucepan.
Put half of the peas into a blender and mix at low speed. Gradually add the chicken broth and olive oil. Process until smooth.
Add the mint, remaining whole peas, mozzarella and sauce to the pasta. Toss well.
Season to taste with salt and pepper.
Serve with a simple tomato salad and garlic bread.