Combine egg yolk, whole egg, Silver Palate Dijon Mustard, salt, pepper and 1 tablespoon of the lemon juice in a food processor. Process for 1 minute. With motor running, drizzle in oil in a slow, steady stream. Once all oil is added, shut motor off and scrape down sides of bowl with a spatula. Taste and correct seasonings, adding more lemon juice if needed. Scrape into a storage container, cover and refrigerate for up to 5 days.