Masoor Dal Tadka (Red Lentil Dal)

Name: Masoor Dal Tadka (Red Lentil Dal)
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Cuisine: Indian
Ingredients: 190 g red lentils (about 1 cup); 711 ml water (about 3 cups (plus more if needed)); 1/2 teaspoon ground turmeric; 1 tablespoon canola oil or ghee; 1 teaspoon cumin seeds; 1 large red onion (halved, peeled, and finely diced); 2 garlic cloves (finely minced); 1 serrano chili (slit in half lengthwise); 1 plum or roma tomato (diced with the juices); 1 teaspoon garam masala; 1 teaspoon ground coriander; 1/2 teaspoon kashmiri chili powder (optional); Salt and black pepper to taste; 1 large garlic clove or 2 small garlic cloves (thinly sliced); 1 teaspoon brown or black mustard seeds (optional); 1 handful fresh cilantro (minced (for garnish)); 1 lime (for serving); Cooked white rice or chapati (for serving)