Preparation Preheat oven to 200°F. Thinly spread mustard on a parchment-lined baking sheet. Bake until dried, 1-1 1/2 hours. Let cool; crumble. Place eggs in a small saucepan; add water to cover by 1 1/2". Bring to a boil; remove from heat, cover, and let stand 5 minutes. Drain. Transfer eggs to a bowl of ice water; let cool. Peel; set aside (yolks should still be runny). Toast caraway seeds in a small skillet over medium heat, tossing often, 1 minute. Add grapeseed oil and bread; cook, tossing occasionally, until bread is just golden, about 4 minutes. Let cool, then blend in a blender until as smooth as possible; set rye oil aside. Blend eggs, vinegar, and lemon juice in a clean blender until smooth. With motor running, slowly add rye oil, then olive oil; blend until aioli is thickened. Pass through a sieve into a small bowl; season with salt. Spread aioli on plates, top with ham, and sprinkle with mustard powder.
Preparation Preheat oven to 200°F. Thinly spread mustard on a parchment-lined baking sheet. Bake until dried, 1-1 1/2 hours. Let cool; crumble. Place eggs in a small saucepan; add water to cover by 1 1/2". Bring to a boil; remove from heat, cover, and let stand 5 minutes. Drain. Transfer eggs to a bowl of ice water; let cool. Peel; set aside (yolks should still be runny). Toast caraway seeds in a small skillet over medium heat, tossing often, 1 minute. Add grapeseed oil and bread; cook, tossing occasionally, until bread is just golden, about 4 minutes. Let cool, then blend in a blender until as smooth as possible; set rye oil aside. Blend eggs, vinegar, and lemon juice in a clean blender until smooth. With motor running, slowly add rye oil, then olive oil; blend until aioli is thickened. Pass through a sieve into a small bowl; season with salt. Spread aioli on plates, top with ham, and sprinkle with mustard powder.