Creamy Ethiopian Lentils

1 cup brown lentils, sorted for foreign material and rinsed
4 cups fresh baby spinach leaves
3 cups vegetable broth or chicken broth
2 large red yams, peeled and diced
2 Tbsp. olive oil
2 cloves garlic, minced
½ onion, thinly sliced
1 (14.5 oz) can diced tomatoes
1 Tbsp. Ethiopian Berbere seasoning
1 inch of fresh ginger, peeled
1 (14 oz) can light coconut milk