You can use different combinations of grains and legumes for flavor and texture in this savory recipe. Fruit and vegetables embellish the dish and add even more interest.
Wild rice: In 6-quart pot, heat oil over high heat. Add onions and thyme and cook, stirring often, until onions are just wilted. Add wild rice, stir to coat and cook, stirring, 3 minutes. Add salt and 4 quarts cold water. Cover and bring to a boil. Reduce heat to medium and cook until liquid has evaporated and rice begins to pop open, 35 to 40 minutes. Remove from heat and set aside to cool.
Meanwhile, make basmati rice: In 4-quart pot, heat 1/2 cup oil over high heat. Add saffron and cook, stirring, 30 seconds. Add rice and stir to coat. Add salt and 2 quarts plus 1 cup cold water, stir and bring to a boil. Stir in remaining 1/2 cup oil, reduce heat to medium and simmer, uncovered, until liquid has evaporated and rice is tender, 12 to 15 minutes. Transfer to tray, spreading rice out to cool; set aside.
In 4-quart pot, heat 1/4 cup oil over high heat. Add leeks and cook, stirring often, until wilted, about 2 minutes. Add garlic, oregano, thyme and rosemary and cook, stirring, 1 to 2 minutes. Add beans and stir to coat, then stir in broth. Cover and bring to a boil. Reduce heat to low and simmer until beans are tender but not mushy, about 40 minutes. Remove from heat and cool.
In very large bowl, combine both rices, beans, apricots, celery and chervil. In medium bowl, whisk together vinegar and remaining 3 cups oil and sprinkle over rice mixture to taste. Toss gently to combine and serve at room temperature.
Do ahead: The rices and beans can be cooked up to 4 days ahead and refrigerated separately. The dish can be assembled up to 8 hours ahead.