How to get and use class/entity type by reflection?

I have these entities that are being called at runtime and I need to be able to return an IQueryable<EntityObject> based on the entity type being called that particular time by string. Let's say the entity is types of food and the class name is Food, so...

return Repository.Read<Food>();    //this is what I am trying to accomplish

However, I don't know that it is Food until runtime and is such only given as a string, so I use reflection:

Type t = Type.GetType(lookupEntityName);    //where lookupEntityName = "Food"

How can I use this Type t to replace 'Food' in the original line of code from above:

return Repository.Read<HERE>();    // use 't' to repalce "HERE"