Heat 2 tbsp avocado oil in a large skillet over medium-high heat until shimmering.
Add 1 cup diced onion, 1 tbsp grated ginger, 3 garlic cloves (finely minced), 1 tsp ground coriander, 1 tsp ground cumin, 1 tsp turmeric, and salt to taste. Sauté, stirring occasionally, for about 5 minutes, until the onion is beginning to soften and the spices are fragrant.
Pour in 1 cup broth and stir, scraping up any browned bits from the bottom of the skillet.
Add 1 cup rinsed red lentils and the 13.6 oz can coconut milk (full fat). Stir to combine.
Increase heat to bring the mixture to a gentle boil, then reduce heat to low or medium-low to maintain a simmer. Simmer, uncovered, for 20–25 minutes, stirring occasionally, until the lentils are soft and the dal has thickened to your liking.