Heat olive oil in a large pan over medium heat.
Add the minced garlic and ginger, and sauté until fragrant.
Stir in garam masala, cumin, coriander, and salt, letting the spices toast for about 30 seconds.
Add the diced onion and carrot, and sauté until they begin to soften.
Pour in the crushed tomatoes, followed by the lentils and coconut milk. Stir well to combine.
Bring the mixture to a gentle simmer, cover, and cook for about 20 minutes, stirring occasionally, until the lentils are tender.
Stir in the spinach and let it wilt into the curry.
Taste and adjust seasoning, adding more salt or maple syrup if needed.