Place the pumpkin seeds, cranberries, garlic cloves, and lemon juice in a food processor and process until very finely chopped. While the food processor is running, slowly drizzle in the olive oil. Blend for about three minutes, scraping down sides and top twice in middle. Season with salt, pepper, and sugar.

Put green beans in a large pot of well-salted boiling water until bright green in color and tender crisp, approximately eight minutes for fresh beans, less for frozen. Drain and place in a bowl of cold water to stop the cooking. Arrange the green beans on a serving plate and spoon the pesto on top.