Database schema:

CREATE TABLE "Dish" (
	id INTEGER -- example: ['2', '1'],
	name TEXT -- example: ['Consomme printaniere royal', 'Chicken gumbo'],
	description TEXT -- example: [''],
	menus_appeared INTEGER -- example: ['8', '111'],
	times_appeared INTEGER -- example: ['8', '117'],
	first_appeared INTEGER -- example: ['1897', '1895'],
	last_appeared INTEGER -- example: ['1927', '1960'],
	lowest_price REAL -- example: ['0.2', '0.1'],
	highest_price REAL -- example: ['0.8', '0.4'],
	PRIMARY KEY (id)
)


CREATE TABLE "Menu" (
	id INTEGER -- example: ['12464', '12463'],
	name TEXT -- example: ['', 'The Modern'],
	sponsor TEXT -- example: ['HOTEL EASTMAN', 'REPUBLICAN HOUSE'],
	event TEXT -- example: ['[DINNER]', 'BREAKFAST'],
	venue TEXT -- example: ['', 'COMMERCIAL'],
	place TEXT -- example: ['HOT SPRINGS, AR', 'MILWAUKEE, [WI];'],
	physical_description TEXT -- example: ['CARD; ILLUS; COL; 7.0X9.0;', 'CARD; 4.75X7.5;'],
	occasion TEXT -- example: ['', 'EASTER;'],
	notes TEXT -- example: ['', 'WEDGEWOOD BLUE CARD; WHITE EMBOSSED GREEK KEY BORD'],
	call_number TEXT -- example: ['1900-2822', '1900-2825'],
	keywords TEXT, 
	language TEXT, 
	date DATE -- example: ['1900-04-16', '1900-04-15'],
	location TEXT -- example: ['Hotel Eastman', 'Republican House'],
	location_type TEXT, 
	currency TEXT -- example: ['Dollars', 'Cents'],
	currency_symbol TEXT -- example: ['$', 'c'],
	status TEXT -- example: ['complete'],
	page_count INTEGER -- example: ['2', '4'],
	dish_count INTEGER -- example: ['67', '34'],
	PRIMARY KEY (id)
)


CREATE TABLE "MenuItem" (
	id INTEGER -- example: ['2', '1'],
	menu_page_id INTEGER -- example: ['3079', '1389'],
	price REAL -- example: ['0.6', '0.4'],
	high_price REAL -- example: ['1.0', '3.0'],
	dish_id INTEGER -- example: ['2', '1'],
	created_at TEXT, 
	updated_at TEXT, 
	xpos REAL -- example: ['0.438571', '0.111429'],
	ypos REAL -- example: ['0.261922', '0.254735'],
	PRIMARY KEY (id), 
	CONSTRAINT fk_menuitem_dish FOREIGN KEY(dish_id) REFERENCES "Dish" (id),
	CONSTRAINT fk_menuitem_menupage FOREIGN KEY(menu_page_id) REFERENCES "MenuPage" (id)
)


CREATE TABLE "MenuPage" (
	id INTEGER -- example: ['119', '120'],
	menu_id INTEGER -- example: ['12461', '12460'],
	page_number INTEGER -- example: ['2', '1'],
	image_id REAL -- example: ['1603595.0', '1603596.0'],
	full_height INTEGER -- example: ['5428', '7230'],
	full_width INTEGER -- example: ['5428', '7230'],
	uuid TEXT -- example: ['510d47e4-2956-a3d9-e040-e00a18064a99', '510d47e4-2955-a3d9-e040-e00a18064a99'],
	PRIMARY KEY (id), 
	CONSTRAINT fk_menupage_menu FOREIGN KEY(menu_id) REFERENCES "Menu" (id)
)

Question: What is the average number of dishes per menu in the Souper de Luxe menus? Identify what is the name of the dish that appeared the most in all of its menus.
Evidence: average number of dishes per menu = DIVIDE(COUNT(dish_id), COUNT(menu_page_id)); Souper de Luxe is a name of menu; dish that appeared the most in all of its menus refers to MAX(COUNT(dish_id));

SQL:
SELECT COUNT(*), T1.dish_id FROM MenuItem AS T1 INNER JOIN MenuPage AS T2 ON T1.menu_page_id = T2.id INNER JOIN Menu AS T3 ON T2.menu_id = T3.id INNER JOIN Dish AS T4 ON T1.dish_id = T4.id WHERE T3.name = 'Souper de Luxe' GROUP BY T3.id ORDER BY COUNT(T1.dish_id) DESC LIMIT 1