Preheat your oven to 400°F.
Drain and rinse the chickpeas, then pat them very dry with a paper towel.
Toss the chickpeas with half of the olive oil and a pinch of salt, then roast on a baking sheet for 20-25 minutes until crunchy.
Season the chicken breast with salt and pepper, then grill over medium-high heat for about 6-7 minutes per side until the internal temperature reaches 165°F.
In a small bowl, whisk together the tahini, lemon juice, and the remaining olive oil, adding a teaspoon of warm water at a time until it reaches a smooth, pourable consistency.
Slice the grilled chicken into thin strips.
In a large bowl, combine the mixed greens, halved cherry tomatoes, and sliced cucumber.
Top the salad with the grilled chicken and roasted chickpeas, then drizzle the lemon tahini dressing over the top before serving.