To make the mimosa vinaigrette: In a jar with a tight-fitting lid, add: the mandarin juice, Champagne vinegar, Dijon mustard, garlic, hot chile flakes, extra-virgin olive oil, wildflower honey, sea salt, and freshly ground black pepper. Close the jar tightly and shake vigorously for 30 seconds to emulsify. To make the zucchini blossoms: In a big bowl, combine the flour, onion powder, sea salt, honey brown beer, and egg. Whisk until smooth. Heat a 1/4-inch of extra-virgin olive oil in a frying pan over medium-high heat. Add a few drops of the beer batter to the oil. When the batter starts to sizzle, the oil has reached the appropriate heat for frying, 375 degrees F. Dip the zucchini blossoms in the honey brown beer batter and then delicately fry them for a few seconds, until they are golden on all sides. Remove the zucchini blossoms from the pan with slotted spoons and strain them on a wire rack to remove any excess oil. Lightly sprinkle with sea salt. Serve immediately with the dipping sauce on the side.