Set a large Dutch oven or other heavy pot on the stove over medium heat.

Add the olive oil to the pot and let it warm for about 30 seconds.

Put the ham steak pieces into the pot. Cook for 4 to 5 minutes, stirring once or twice, until the pieces look glossy and browned at some edges.

Add the chopped onion, diced carrots, and diced celery to the pot. Cook for 6 to 8 minutes, stirring now and then, until the vegetables soften and the onion turns translucent.

Add the chopped garlic to the pot. Stir for 30 seconds, just until it smells fragrant.

Add the tomato paste and dried thyme. Stir for 1 minute so the tomato paste coats the vegetables and darkens slightly.

Add the rinsed lentils to the pot. Stir for about 30 seconds to coat them with the tomato mixture.

Pour the chicken broth into the pot. Add the kosher salt and scrape the bottom of the pot with a wooden spoon to loosen any browned bits.

Raise the heat to high and bring the pot to a full boil.

Lower the heat to medium-low so the liquid bubbles gently. Cover the pot partway, leaving a small gap for steam to escape, and cook for 20 minutes.

Remove the lid and stir the stew. Add the drained chickpeas to the pot.

Keep the pot at a gentle simmer and cook for 10 to 15 minutes more, until the lentils are tender but still holding their shape and the broth looks a little thicker.