Heat the olive oil in a 4-quart / 3.8 L pot over medium heat. Add the onion, carrots, celery, and a pinch of salt. Cook for 6 to 8 minutes, stirring now and then, until softened.
Add the garlic, cumin, smoked paprika, and red pepper flakes. Cook for 1 minute, stirring, until fragrant.
Pour in the crushed tomatoes, chickpeas, and vegetable broth. Drop in the bay leaf and stir everything together. Bring to a simmer.
Reduce the heat to low, partially cover the pot, and simmer for 20 minutes, stirring occasionally, until the stew has thickened slightly.
Remove the bay leaf. Stir in the spinach in two batches, letting each batch wilt for about 1 minute before adding the next.
Stir in the lemon juice. Taste the stew and adjust the salt and pepper.
Ladle the stew into bowls. Top with crumbled feta and chopped parsley, and serve warm.