Heat a dry skillet over medium heat and toast the cumin seeds for about 1 minute, stirring occasionally, until fragrant and lightly golden. This releases their essential oils and deepens their flavor. While the cumin toasts, slice the celery stalks into 1/4-inch thin diagonals and slice the red onion into thin half-moons. Set both aside on a cutting board.

In a large bowl, combine the white wine vinegar, sugar, toasted cumin seeds from Step 1, and salt. Stir until the sugar dissolves completely. Add the sliced celery and red onion from Step 1, tossing gently to coat everything evenly. Let the mixture sit for 15 minutes at room temperature—this allows the vegetables to soften slightly and absorb the tangy, aromatic dressing, which is the foundation of this salad's bright flavor.

While the vegetables are marinating, drain and rinse the cannellini beans, then crumble the feta into large 1/2-inch chunks (I prefer Goya beans for their firm texture, which holds up beautifully in a salad). Roughly chop or tear the fresh mint leaves, keeping them fairly coarse. After the 15-minute rest, add the beans, feta chunks from Step 3, mint, chopped parsley, and olive oil to the bowl with the pickled vegetables. Gently toss everything together until well combined, being careful not to break up the feta chunks too much.

Taste the salad and season with additional salt and black pepper to your preference. The salad is best served at room temperature, which allows all the flavors to meld beautifully and the fresh herbs to shine. If making ahead, you can refrigerate it for up to 2 hours, but let it come back to room temperature before serving for the best flavor.