In a medium saucepan with a tight-fitting lid, melt the butter over medium heat. Add the orzo and toast until deep golden and fragrant. Stir in the rice, add about 2 cups chicken stock and bring to a simmer. Cover and cook, stirring occasionally and adding a bit more stock if the rice begins to stick, until the rice is just tender, about 18 minutes.
Meanwhile, in a soup pot, heat 2 tbsp. EVOO over medium-high heat. Add the carrots and leeks; season with salt ad pepper. Cook stirring, until softened, 6 to 7 minutes. Add the remaining stock and the fresh peas (if using frozen, stir in just before serving). Bring to a boil, then lower to a simmer.
Using a food processor mix the parsley, mint, cheese, pine nuts, garlic and about 1/4 cup EVOO into a pesto. Stream in more EVOO iuf needed. Stir the pesto into the rice pilaf.
Serve 1/2 cup of the prepared rice in each of 4 soup bowls. Top with the peas and carrots in broth. Stir to combine.