Heat oil in a soup kettle over low heat while mincing garlic and measuring spices. When ready to cook, increase heat to medium-high and add garlic, Italian seasonings, and fennel; cook, stirring constantly, until fragrant, a minute or so. Stir in cauliflower to coat. Add broth, tomato sauce, and lentils; bring to boil. Reduce heat to medium-low and cook, stirring occasionally, until cauliflower is tender and liquid has reduced to stew consistency, 10 to 15 minutes. Stir in coconut milk and return to a simmer. Stir in parsley and balsamic vinegar. Taste and adjust seasonings, including salt and pepper, and adding extra water or broth if you prefer a juicier stew. Serve.