Cannelloni di Pesto

Name: Cannelloni di Pesto
Ingredients: 2 Cups milk; 3 1/2 Tablespoons unsalted butter; 1/3 Cup all-purpose flour; Pinch of salt; Pinch of nutmeg; 1 small clove garlic; 1/2 Tablespoon pine nuts; 2 Cups basil; 1/4 Cup parsley; 4-5 tablespoons extra-virgin olive oil; Salt, to taste; 3 Tablespoons pecorino romano, grated finely; 1 Tablespoon Parmigiano-Reggiano, grated finely; 2 Cups ricotta; 1 1/2 Cup Parmigiano-Reggiano, grated finely; Salt and pepper, to taste; 8 fresh cannelloni or lasagna sheets; 1/2 Cup Parmigiano-Reggiano, grated finely; 8 green beans, boiled; 1 small potato, boiled and sliced; Cooking spray or melted butter, for the baking dish