Boil 2 cups rotini according to package directions until just tender—usually 8 to 10 minutes—then drain well without rinsing. (I skip the rinse because starch helps the dressing cling, which is the secret most recipes get wrong.)
While pasta is still steaming hot, transfer it to a large bowl and immediately pour the dressing over top. Toss constantly for a full minute, letting every piece absorb that lemon and oregano while warmth opens the pasta structure.
Let the dressed pasta cool to room temperature—this takes about 15 minutes and actually improves flavor because the dressing continues seeping in. Patience here beats putting it in the freezer, which can make the texture grainy.
Dice your cucumber and halve those cherry tomatoes, keeping them separate until the pasta cools completely. This prevents the acidic tomato juice from turning everything mushy before the cookout even starts.
Toss in the cucumber, tomatoes, red onion, and Kalamata olives once the pasta reaches room temperature. The vegetables stay crunchy because you're adding them to something cool rather than hot, which is why timing genuinely matters here.
Fold in your cooked chicken and crumbled feta last, so the cheese doesn't get buried at the bottom. This Greek pasta salad family summer recipe looks intentional when each ingredient sits visible on top.
Taste and adjust seasoning—sometimes you need an extra pinch of oregano depending on your brand. I always add a tiny squeeze of fresh lemon right before serving because it wakes everything up and reminds people why they loved it the first bite.