Step 1Place the yolk in a stainless steel bowl. Begin whisking in the grape seed oil drop by drop. Once the mixture has thickened and emulsified, whisk in the remaining grape seed oil and the olive oil in a slow, steady stream. If the mixture gets too thick, add a drop or two of water.
Step 2With a mortar and pestle, pound the garlic with one-third teaspoon salt. Whisk the garlic paste into the aioli. Season with one-fourth teaspoon salt, a squeeze of lemon juice, the lemon zest and cayenne. Taste for balance and seasoning. If the aioli seems thick and gloppy, thin it with a little water until creamy.
Step 1In a mixing bowl, stir together the flour, salt and cayenne. Whisk to combine completely, and make a well in the center.
Step 2Place the egg in the well and whisk from the center outward to incorporate the flour. Then whisk in the cold soda water until the batter is smooth. Make this right before deep frying.
Step 1In a large bowl, mix together the ricotta and Gallego cheeses.
Step 2In a medium saute pan, sweat the shallots, thyme and salt and pepper to taste in one-fourth cup olive oil over medium heat until soft and fragrant, 1 to 2 minutes. Cool, and fold the shallots into the cheese mixture.
Step 3Stir in the parsley and season with most of the lemon juice (reserving a squeeze of juice) and additional salt and pepper to taste.
Step 4Carefully stuff the blossoms with the filling, about 2 to 3 tablespoons for each, and twist them at the ends.
Step 5Heat oil for deep frying to 360 degrees. Dip each of the blossoms in the batter to coat, then drop them carefully into the oil. Fry the blossoms in batches for 4 to 5 minutes, until golden brown on all sides. Turn them over halfway through. Drain them on paper towels and season with salt and a squeeze of lemon.
Step 6Toss the parsley leaves and the pepitas in a small bowl with a squeeze of lemon, 2 teaspoons olive oil, salt and pepper to taste.
Step 7Arrange the blossoms on a platter. Spoon the aioli over and around them and scatter the parsley-pepita salad over the top.