Preheat oven to 425F. On a rimmed baking sheet, toss carrots and onion with 2T oil, 1t each of cumin and coriander. Roast until golden brown and tender, about 30-35 minutes, flipping halfway through.
Meanwhile, make the salsa verde. Combine all ingredients (parsley through red pepper flakes) in a medium bowl. Moisten with olive oil until it's damp, but not soupy. Think pesto. Taste and add salt if necessary. It should be a beautiful vibrant green!
Carrots: Transfer roasted carrots and onion to a food processor and pulse to form a very coarse paste. Add the zest of 1 lemon, juice of half a lemon, and salt to taste. Keep this paste chunky, as it will be a nice texture difference against the labne.
To serve: Spread the labne (or greek yogurt/farmer's cheese) over the bottom of a medium, shallow platter. Dollop the smashed carrots atop, spreading the mix so it almost covers the diary, but let some peek through around the edges. Generously spoon the salsa verde over the carrots, then shower the entire dish with toasted pepitas.