You can add a meal idea by clicking on the “Cook” tab and then on the “Add meal” button. You can also just type your meal combination, with items separated by commas, into the plan table by clicking on the “Cook” button for a specific date. For example, you can just enter "Lemon chicken, broccoli, rice" for a meal.
In the plan tab, parts of a meal will automatically link to recipes as long as they are spelled the same.