Place the olive oil, lemon juice, honey, zest, mustard, salt, and pepper in a bowl and whisk until well combined, or add to a small Mason jar, cover with a lid, and shake vigorously until combined. Set aside.
Cook freekeh according to package instructions in either water or broth.
Place the cooked freekeh, lentils, chickpeas, avocados, radish slices, green onions, and mint in a large serving bowl and stir gently to combine. Re-whisk or shake the dressing, drizzle on top, and toss the salad gently to combine.
Season with salt and pepper to taste, and garnish with extra mint leaves.