Rinse the brown lentils in a fine-mesh strainer under cold running water, picking out any debris or damaged lentils.

Transfer the rinsed lentils to a medium saucepan and pour in the water or vegetable broth. Bring to a boil over high heat.

Reduce the burner heat to low, partially cover the pan with the lid, and let the lentils simmer gently for 20 to 25 minutes.

Check for doneness around 15 minutes. The lentils should be tender to the bite but still hold their shape without turning mushy.

Drain any remaining liquid through a fine-mesh strainer and shake gently to dry off excess moisture.

While the lentils cook, combine the extra virgin olive oil, lemon juice, lemon zest, ground cumin, minced garlic, salt, and red pepper flakes in a large mixing bowl. Whisk until fully blended.

Add the warm, freshly drained lentils straight into the bowl with the dressing. Toss thoroughly to coat every lentil, then let rest for 5 minutes to absorb the dressing.

Fold in the diced red bell pepper, red onion, and fresh chopped parsley. Serve warm, at room temperature, or chilled.