Cook wheat berries in a large pot of boiling, salted water (uncovered) until they are soft, about 20 minutes. Drain in sieve.
In skillet, heat 1 tbsp (15 mL) of the oil over medium high-heat. Add red onion and cook, stirring often, until softened, about 5 minutes. Remove from heat.
Pour in remaining oil, vinegar, salt and pepper. Add warm wheat berries, red pepper, cucumber, grapes and basil and toss to combine. Transfer to a bowl and let salad rest for at least 30 minutes, tossing occasionally so the wheat can absorb the dressing.
Sprinkle with feta and serve at room temperature.
Recipe Notes
Per serving: About 290 cal, 6 g pro, 18 g total fat (2 g sat fat), 30 g carb, 4 g fibre, 5mg chol, 360 mg sodium.