Combine lentils and 3 cups of the broth in a medium pot.

Bring to a boil, reduce heat and simmer until lentils are tender but not mushy, 25 to 30 minutes.

Add a few tablespoons water if needed to cover lentils during cooking.

Drain lentils, reserving cooking liquid in a small bowl.

Transfer lentils to a large mixing bowl and set aside.

Slice kale leaves into 1/4-inch-wide strips.

Heat a large high-sided skillet over medium-high heat.

When the pan is very hot, add half of the kale, with water still clinging to the leaves, and cook, tossing with tongs constantly, until leaves are just wilted, about 5 minutes.

Add kale to lentils and repeat with remaining kale.

Add onion to the hot skillet with 1/4 cup water.

Cook, stirring frequently, until the pan is nearly dry, about 5 minutes.

Add garlic and cook for 30 seconds.

Pour in wine and stir to scrape up any browned bits from the bottom of the pan.

Let wine reduce by half, about 2 minutes.

Add sun-dried tomatoes, remaining 1 cup broth and reserved lentil cooking liquid to the skillet.

Simmer until tomatoes are tender and the liquid is reduced by half, about 10 minutes.

Pour onion mixture over kale and lentils. Add fennel, thyme and pepper, and toss well. Serve warm or at room temperature.