Serves 4; can be multiplied and cooked in a larger slow cooker
1 cup brown lentils
2 cups homemade or low-sodium chicken broth
1 leek, white part only, trimmed and chopped
12 oz pre-cooked chicken sausage (I use fontina and spinach flavor or roasted garlic flavor), sliced into rounds
1/2 tsp fresh black pepper, or more to taste
Kosher salt, to taste
2 cups fresh baby spinach leaves
1/4 cup crumbled feta cheese, or more to taste
In a 3-quart slow cooker, add the lentils, chicken broth, leek and sausage. Cook on HIGH for 2-1/2 hours, or on LOW for 5 hours, checking periodically to ensure there is enough liquid to cook the lentils.
After the initial cooking time, when the lentils are almost soft, taste, and add black pepper and salt (if needed). Then stir in the spinach and feta. Cook on LOW for 30 minutes.
Serve hot, or let cool completely and refrigerate, and serve cold.