How to Make It
In a saucepan, cover the navy beans with 8 cups of water. Bring to a simmer and cook until the beans are tender, about 30 minutes. Season the beans with salt and pepper and let cool in the cooking liquid. Drain the beans.
In a saucepan of salted boiling water, cook the peas until just tender, about 2 minutes. Drain and cool the peas in a bowl of ice water; drain well.
In a small skillet, toast the flaxseeds, sesame and mustard seeds over low heat until golden and starting to pop, about 2 minutes. Scrape the seeds into a large bowl. Add the beans, peas, peanuts, shallot, vinegar, sesame oil and peanut oil and toss to evenly coat. Season with salt and pepper. Let marinate for 10 minutes or overnight before serving.