Prep the bread: Preheat your oven to 375°F (190°C). Arrange baguette slices on a baking sheet and brush both sides lightly with olive oil. Sprinkle with a pinch of salt.
Toast the crostini: Bake for 8–10 minutes, flipping halfway, until they’re golden at the edges and crisp.
Let them cool slightly so the butter doesn’t melt right off.
Make the herb butter: In a small bowl, combine softened butter, olive oil, garlic, lemon zest, lemon juice (if using), and chopped herbs. Season with a pinch of salt and pepper. Stir until smooth and spreadable.
Slice the radishes: Use a sharp knife or mandoline to slice the radishes very thin.
The thinner the slice, the more delicate the bite. Pat dry with a paper towel if they’re watery.
Assemble: Spread a generous layer of herb butter on each crostino. Shingle a few radish slices on top.
Add a small tuft of sunflower sprouts.
Finish and serve: Sprinkle with flaky sea salt and a crack of pepper. Add a tiny drizzle of olive oil or a pinch of red pepper flakes if you like a little heat. Serve immediately while the bread is still lightly warm.