Using a food processor, puree the orange tomatoes. Pour into a medium saucepan and add the chicken broth and saffron. Bring to a simmer over medium heat, then keep warm over low heat.
In a deep skillet, heat 2 tablespoons EVOO, 2 turns of the pan, over medium heat. Add the onion and garlic; season with salt and pepper and cook until softened, 2 to 3 minutes. Stir in the rice to coat with the oil, increase the heat to medium-high and cook for 2 minutes. Stir in the wine and cook until slightly evaporated, about 1 minute. Stir in a couple ladlefuls of the warm tomato broth, stirring constantly until absorbed, about 1 minute. Continue adding the broth, a couple of ladlefuls at a time, stirring after each addition until absorbed and to prevent sticking. Cook until the rice is tender and the mixture is creamy but not soupy, about 18 minutes. During the last 2 minutes of cooking, stir in the butter.
In a bowl, toss the arugula and grape tomatoes with the lemon juice and remaining 1 tablespoon EVOO; season with salt and pepper.
Stir the cheese into the risotto; season with pepper. Serve in shallow bowls topped with the salad.