The zucchini flowers add a peppery fragrance, but they can be omitted if you can't find them at the market. If you've got your grill going for other dishes, by all means use it to toast the bread.Plus: More Appetizer Recipes and Tips
Preheat the oven to 450°. Loosely wrap the beets in foil and roast for about 1 hour, or until tender. Let cool slightly, then peel the beets and cut them into 1/2 -inch dice. Combine the beets with 2 tablespoons of the olive oil, the vinegar, rosemary, crushed red pepper and a generous pinch each of salt and black pepper.
Heat a grill pan. Lightly brush the bread on both sides with the remaining 2 tablespoons of olive oil and grill until crisp and golden. Fold the zucchini flowers into the beet mixture, divide evenly among the grilled bread slices and serve.
The peeled beets can be refrigerated for up to 2 days.