In a large pot, warm the olive oil over medium heat. Add the meat, break into chunks, and let cook undisturbed for 3 minutes, then break into small pieces. Add onion, carrots, celery, and ½ teaspoon salt and cook until softened, stirring occasionally, about 5 minutes.
Add the garlic, tomato paste, fennel, oregano, and red pepper flakes (if using) and cook, stirring occasionally, for about 30 seconds.
Stir in the potatoes, lentils, coconut milk, water, and remaining 1 teaspoon salt. Stir in the tomatoes and their juices, using your hands to crush the tomatoes into small chunks as you add them to the pot (or use scissors, see video and be careful of splatter!).
Cover and bring to a boil over high heat, then reduce the heat to low and simmer, covered, until the lentils are cooked through, about 30-40 minutes, stirring halfway. Turn off the heat, stir in the kale, and cover to let the steam help soften the kale, about 2 minutes.
Serve the soup drizzled with good olive oil and some fresh black pepper.