Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to make stuffed shells [title] Cook 15 pasta shells al dente. [step] Each pasta shell should be a bit bigger than the palm of your hand. Just place the shells in boiling water and cook them over medium heat until they're firm but not too hard.

Ending1: Keep in mind that the shells won't hold up against high heat. [title] Add your favorite ingredients : [step] 1 tbsp. Ending2: [substeps] Some people like to taste the shells in rice to test and to get used to the different textures and flavors. Check on them frequently in between meals to make sure they are firm but soft. Ending3: This can take anywhere from 5 to 15 minutes to be finished. [title] Transfer the shells to a food processor or a deep pan and blitz them. Ending4: Read the instructions on the package to see exactly how long they should be cooked. Drain and separate the shells when they're cooked.

Answer format: ending1/ending2/ending3/ending4