If you have a really large bunch of collards, you may need to increase the amount of the yogurt/mustard mixture.
1/3 c plain yogurt
1 T Dijon mustard
1 bunch collard greens
1 T vegetable oil
1/2 c diced onion
salt, to taste
1. Combine yogurt and mustard and set aside.
2. Bring a pot of water to the boil. Stem the collards. Stack and cut the collards in 1-inch strips, then chop. Add the greens to the boiling water. Cook for 10 minutes or until just tender or to your preference. Drain, reserving some cooking liquid.
3. Heat the oil in a large skillet over medium heat. Add the onion and cook until soft, about 5 minutes. Stir in the collards and salt. Reduce the heat and stir in the yogurt mixture. Cook about 5 minutes or until the liquid evaporates. If the liquid seems to be cooking off too quickly, splash in some of the reserved cooking liquid, cooking until this has evaporated.