This recipe is really more of a "technique". The vegetable layer could be pretty much whatever you like - I think it would be good with some sauteed pancetta and leeks... or spinach and mushrooms, or onions and ham... or nothing at all!! As for cheese, I used gruyere, but any hard cheese would work - or could be left out as well.
Pre heat the oven to 325 degrees. Spray 4 small ½ cup ramekins with cooking spray. Set aside. In a small bowl combine the thyme, artichoke hearts, tomatoes and olive oil. Season with salt and pepper. Divide mixture among the ramekins. Fill a small bowl with cold water. Separate the eggs, placing the yolks in the bowl of cold water. In the bowl of an electic mixer fitted with the whisk attachment. , add the egg whites, salt, pepper and the cream of tartar. Beat the egg whites until stiff peaks form - about 5 to 7 minutes. Slowly beat in the cheese.
Mound the whipped egg whites into the four ramekins (the egg whites will be higher than the edge of the ramekin. Using a small spoon, make an indentation in the top of the egg whites to hold the egg yolk. Using your fingers, gently remove each egg yolk and place in the indentation. Drizzle a little milk or cream over the egg yolk and season with salt and pepper. Place the ramekins on a rimmed baking sheet and bake for 10 - 12 minutes or until whites are golden and egg yolk is barely set. Serve immediately!
Although you can't bake the eggs ahead of time, you can separate the eggs, cover, and refrigerate the day before as well as assembling the vegetables the day before - just cover and refrigerate.