Toss the cauliflower with 2tbsp olive oil and spread them evenly on a rimmed baking sheet. Sprinkle with salt and pepper. Bake for 25~30 minutes, or until the florets start getting brown and crispy. Cool to room temperature.
Combine freekeh and 1½cups of water or broth in a medium saucepan and bring to a boil. Lower the heat, simmer covered for 20~25 minutes, until the freekeh is tender and has absorbed all of the liquid. Fluff freekeh with fork and cool slightly.
In a small bowl, combine 3tbsp olive oil, lemon juice, mustard, salt and pepper; whsik well until combined.
In a large bowl, gently stir together roasted cauliflower, freekeh, currants and lemon zest. Drizzle with the dressing and mix until all ingredients are evenly coated. Taste and adjust the seasonings. Stir in the mint, just before serving.
Serve cold or at room temperature. Any leftovers can be stored in an airtight container for up to 3 days.