For lentil soup you need:
As much chopped leeks as you can handle. Should cover the bottom of the pot at least. Leeks are huge, cheap, delicious, and freeze really well chopped, so I always keep them stocked. You can use onions instead, but I think leeks are much better for soup.
2-3 medium carrots, quarter slices
2-3 celery, sliced
2-3 cloves garlic
2 cups dry/raw green or brown lentils or split green peas
2 tablespoons tomato paste
1/2 cup pearled barley or orzo pasta (or other pasta/grain, or just use more lentils)
Half bunch kale leaves in bite size pieces
Extra virgin olive oil
Juice of 1/2 lemon or white vinegar
Salt, pepper, paprika
Optionally, bay leaves and turmeric
Step 1: heat a pot with oil and cook your leeks, carrots, and celery until soft. Leeks cook a bit longer.
Step 2: add the spices and let them bloom. Add tomato paste and stir until sauce forms.
Step 3: stir in lentils/peas and barley/orzo.
Step 4: add 7 cups water (adjust to preference) and bring to a boil, then let simmer. Cook for 30-45 minutes (or 15-20 in pressure cooker) depending on the lentils/peas you picked. Lentils are done when they are just about bursting.
Step 5: add lemon and kale
Obviously, a lot of this is to taste. If you don’t have good fresh veggies, the broth can be a little flavorless. You can add a bit more lemon and salt, or bullion if it’s really bland. If you know the veggies aren’t great, just use more of them in the first step. You can also use less water.
You can broil the kale with a bit of olive oil and salt for 3-4 minutes until it’s crispy before adding to the soup. This will give it a less fibrous, more crunchy character.