Step 1In a blender, beat together the mustard, egg yolks and garlic. Slowly drizzle in the canola oil until emulsified, adding ice water if needed to thin the mixture and keep it cool. Beat in lemon juice to taste, then slowly beat in the olive oil. Season with ½ teaspoon salt, or to taste. Pass the mixture through a fine strainer, discarding any garlic solids. This makes about 2 cups aioli, which will keep, covered and refrigerated, up to 1 week.
Step 1In the bowl of a food processor, pulse together the egg yolks, Dijon mustard, mustard powder, lemon juice and aioli until smooth. Pass the mixture through a very fine strainer into a bowl. Fold in the horseradish, whole grain mustard and parsley. Season with ¼ teaspoon salt and a pinch of pepper, or to taste. This makes about 1 ¾ cups yolk mixture.
Step 2Prepare the garnishes: Very finely slice the radishes and set aside. In a small bowl, toss the chives with a little rice wine vinegar and olive oil to coat.
Step 3To prepare the eggs, fill the cavity of each egg white with yolk mixture. Top with flaked smoked fish, a radish slice and a sprinkling of chives.