- 1 large egg yolk
- 1 garlic clove, finely grated
- 1 tsp finely grated lemon zest
- 2 tbsp (or more) fresh lemon juice
- 1 tsp Dijon mustard
- Kosher salt
- 1 cup vegetable oil
- 8 oz lump crabmeat, picked over
- 2 tbsp chopped fennel fronds
- 1 to 2 serrano chiles, seeded, finely chopped
- 6 tbsp extra-virgin olive oil, divided
- Kosher salt
- 4 3/4″-thick slices country-style sourdough bread
- lemon wedges, for serving
- Whisk egg yolk, garlic, lemon zest and juice, mustard, and a large pinch of salt in a medium bowl. Whisking constantly, slowly drizzle in oil, drop by drop at first, until aioli is thickened and smooth; season with salt and more lemon juice, if desired.
- Toss crabmeat, fennel fronds, 1 chile, and 2 tbsp oil in a medium bowl. Season with salt; add more chile, if desired.
- Drizzle both sides of bread with remaining 4 tbsp oil; working in batches, toast in a large skillet over medium-high heat until golden brown, about 2 minutes per side.
- Spread each piece of toast with 1 tbsp aioli. Top with crabmeat; cut each toast into 4 pieces. Place a small dab of aioli in center of each piece; serve with lemon wedges. (Extra aioli can be used for dressings or dips.)