How to redirect to state if specific stateParam is empty

I'm not sure if the way I am doing it is correct, any advice would be appreciated.

I have a Restaurant Selector, which the user can select a restaurant from. Then all other child states load up content specific to the restaurant selected. But I need to have a child state selected by default, including a restaurant, which will be either selected based on the users closest location or on cookie data if they have previously selected one. But, i'm not sure how I can redirect to a child state by default without knowing the restaurant id already?

A bastardised version of my code below to illustrate.

app.config(function ($stateProvider, $urlRouterProvider) {
$urlRouterProvider.otherwise("/restaurant/[some id based on cookie info]/our-food"); // if no id is set, then I want to get it from a cookie, but then how do i do the redirect?

$stateProvider
    .state('restaurant', {
        url: '/restaurant/:restaurantId',
        template: "<ui-view/>",
        controller: function($state, $stateParams, Data, RestaurantService, $cookieStore) {
            if(typeof $stateParams.restaurantId !== 'undefined') {
                                  // get the restaurantID from the cookie
                            }
        }
    })
    .state('restaurant.our-food', {
        url: '/our-food',
        templateUrl: function($stateParams) {
        return 'templates/food-food.html?restaurantId=' + $stateParams.restaurantId;
        },
    controller: 'SubNavCtrl'
    })
    .state('restaurant.glutenfree-vegetarian', {
        url: '/glutenfree-vegetarian',
        templateUrl: function($stateParams) {
    return 'templates/food-vegetarian.html?restaurantId=' + $stateParams.restaurantId;
        },
    controller: 'SubNavCtrl'
    })

An image below to illustrate what is happening on the front end: www.merrywidowswine.com/ss.jpg