In a large nonstick frying pan, bring one (1) inch of lightly salted water to a boil. Add the cauliflower florets, cover and cook over high heat until just tender, about 12 minutes. Using a slotted, spoon, transfer the cauliflower florets to a bowl; reserve the cooking liquid.
Heat 1 tablespoon of the olive oil in the same frying pan. Add the onion and garlic; cook over medium heat, stirring occasionally, until golden. NOTE: Watch the onion carefully, as you do not want them to burn. They should be a lightly golden.
Add the cooked cauliflower, fennel seeds, and a pinch of salt and pepper. Cook, stirring occasionally, until the cauliflower is very tender, about 8 minutes; add a few tablespoons of the cooking liquid if it begins to look dry. NOTE: I ended up adding 12 tablespoons of the cauliflower liquid (one tablespoon at a time during the cooking process) to keep the mixture moist.
Mash the cauliflower to a chunky purée and season with salt and pepper to taste; set aside.
Arrange bread slices in one layer on a large baking sheet; brush both sides with olive oil. Bake in middle of oven until very lightly toasted, about 10 to 15 minutes.
To serve: Sprinkle the toasted bread slices with coarse salt; spoon the cauliflower mixture on top. Drizzle with a little olive oil, garnish with the parsley and serve.
Makes 8 servings.
Cauliflower Crostini Recipe: https://whatscookingamerica.net/Appetizers/CauliflowerCrostini.htm