- Remove tender, leafy parts of kale and mustard greens from their tough stems and place in a large bowl. Cover with cold water and wash greens, allowing dirt to sink to the bottom. Transfer greens into a colander or strainer to drain thoroughly.
- Bring a large pot of generously salted water to a rolling boil over high heat. Add drained kale and mustard greens, using a spatula to make sure they are immersed. Bring back to a boil; cook until barely tender and not soft, 3 to 4 minutes. Transfer to a bowl and let cool until easily handled.
- While greens are cooling, heat 3 tablespoons butter in a pan over medium heat. Saute garlic, green onions, and salt until they soften and turn translucent, about 5 minutes. Stir in black pepper and cayenne.
- Squeeze water from cooled greens and chop. Add greens to the pan and continue to cook and stir until just heated through, 2 to 3 minutes. Taste and adjust for seasoning. Remove from heat and stir in rice vinegar.
- Heat about 2 tablespoons butter in a pan over medium-low heat. Add 2 slices French bread; place 1/4 of the Irish Cheddar cheese on top. Place about 1/2 cup of braised greens on 1 slice of bread; top with remaining bread slice, cheese side-down. Cook, flipping as needed, until surface is golden brown and crisp, cheese is melted, and greens are heated through, 2 to 3 minutes.
- Repeat with remaining bread, cheese, and greens. Remove to a cutting board, slice in half at a slight angle, and serve.
% Daily Value *
Total Fat: 76 %
Cholesterol: 45 %
Sodium: 45 %
Potassium: 27 %
Total Carbohydrates: 18 %
Dietary Fiber: 27 %
Protein: 57 %