Combine rinsed quinoa, water, and salt in a medium saucepan. Bring to a boil over high heat, then reduce heat to low, cover, and simmer for 15 minutes until water is absorbed and quinoa tails have unfurled. Remove from heat and let stand covered for 5 minutes. Fluff with a fork and spread on a baking sheet to cool completely, about 10 minutes.

While quinoa cooks, dice the bell pepper and red onion. Rinse the diced onion under cold water for 30 seconds to mellow its bite, then drain well. If using frozen corn, thaw under warm running water and drain thoroughly. Pat all vegetables dry with a clean kitchen towel to prevent a watery salad.

In a large mixing bowl, whisk together lime juice, olive oil, cumin, garlic, honey, salt, and black pepper until emulsified. Taste and adjust - the dressing should be bright and assertive since it will mellow against the mild quinoa.

Add the cooled quinoa, black beans, corn, bell pepper, onion, and cilantro to the bowl with the dressing. Toss thoroughly to coat every grain. Let sit at room temperature for 15 minutes if possible, or refrigerate for up to 4 hours to let flavors meld. Taste again before serving and add more lime juice or salt as needed.

Transfer to a serving bowl and top with additional cilantro. Serve chilled or at cool room temperature. The salad keeps beautifully for 4 days refrigerated.