Put quinoa and 3 cups water in a small saucepan over high heat. Bring to a boil. Reduce heat to low, then cover and simmer until all the water is absorbed, about 15 minutes.
Meanwhile, put cranberries in a small heatproof bowl. Cover with boiling water and soak 10 minutes. Put mixed seeds in a frying pan over medium heat and cook, stirring occasionally, 3-4 minutes, or until they start to brown. Tip into a salad bowl.
Drain cranberries. Add to salad bowl with mixed beans, parsley and quinoa. Stir to mix well.
Put vinegar, oil, and pepper to taste in a small bowl. Whisk together, then stir dressing through salad. Serve immediately, or refrigerate until required.
You can use couscous instead of quinoa and replace the mixed seeds with toasted walnuts or pine nuts. Add mint or spring onions (scallions).
Rinse quinoa well before use, to remove the bitter-tasting saponin layer from the surface of the grains.
If time permits, reserve the liquid from the soaking cranberries and add it to the quinoa during cooking.