Soak 1/2 cup minced red onion in cold water, 10 minutes; drain and rinse. Grate 4 halved plum tomatoes into a bowl. Add 3 tablespoons olive oil, the juice of 1 orange, 1/2 teaspoon cayenne, 1 diced bell pepper, the onion, 1 drained can pinto beans and 1 teaspoon salt. Stir in 2 cups cold cooked rice and some chopped cilantro and scallion. Season with salt and pepper.