I don't know the restaurant but here is a recipe I've used for many years
HOT ARTICHOKE AND SPINACH SPREAD
1 large can artichoke hearts (in water not oil), drained and chopped
1 small can chopped green chilies, drained
1/2 box frozen chopped spinach, thawed and squeezed dry
1 garlic clove, minced
1 cup mayonnaise (I use homemade)
1 handful Parmesan cheese
2 tbs. sliced green onions
2 tbs. seeded, chopped tomato
Heat oven to 350 F. Mix all ingredients except onions and tomatoes until well blended. Spoon into shallow ovenproof dish or 9-inch pie plate. Bake 20 to 25 minutes or until lightly browned. Sprinkle with onions and tomatoes.