Tortellini with Spinach Walnut Pesto

Name: Tortellini with Spinach Walnut Pesto
Ingredients: 4 ounces chopped walnuts; 2 family size (18-ounce) packages, cheese or mushroom and cheese filled fresh tortellini (sold on dairy aisle of market); 1 cup chicken stock or broth; 10 ounces (1 package) baby spinach, reserve a few leaves for garnish; 2 cloves garlic; 2/3 cup (a couple of handfuls) grated Parmigiano or Romano; 1/4 teaspoon ground nutmeg or freshly grated; 1/4 cup extra-virgin olive oil; Salt and pepper; Edible flowers, optional plate garnish, nice for parties