Prepare artichoke bottoms: In a large, nonreactive pot whisk flour with a little water to make a smooth paste; whisk in about 1 quart of water and add salt. Squeeze juice from lemon half into water, then add peel. Bring to a boil, simmer 5 minutes and add artichoke bottoms. Cover, reduce heat to simmering and cook until artichokes are tender, and base can be pierced with tip of a knife, 25 to 30 minutes. Let artichokes cool in their liquid. When artichokes are cool enough to handle, use a small spoon to scoop out chokes. Use a sharp knife to trim any remaining leaves.
Prepare creamed spinach: In a skillet heat oil with onion and garlic over medium heat until tender. Add spinach in handfuls, stirring until it reduces and releases its liquids. Cook until liquid evaporates, 2 minutes. Fold in warm b»chamel sauce and season to taste with Tabasco, salt and pepper. Keep warm.
Poach eggs: In a shallow saucepan or skillet bring 2 inches cold water and vinegar to a boil over medium heat. Reduce heat until water simmers gently. Break eggs, one at a time, into a ramekin or coffee cup; holding ramekin as close as possible to water, gently slip egg into water. Poach eggs 3 minutes for very soft-cooked, 5 minutes for medium-soft. Using a slotted spoon, scoop out eggs and if necessary, gently pat dry with paper towels. Season with salt and pepper.
To assemble: Make a bed of spinach on 2 warmed plates and top with artichoke cups. Spoon a little Hollandaise sauce into cups and top with poached eggs. Spoon remaining sauce over eggs and serve immediately.
Yield: 2 servings