"Sofern du das Essen magst, ist es gut."
I figured it out. The reason is that when a subordinate clause is at the beginning of a sentence, the word order is Subordinate Clause -> VERB -> Rest of sentence. So in this case, "Sofern du das Essen magst" is the subordinate clause because it doesn't mean anything on its own in this sentence. Then the verb, "ist" must come next, then the rest of the sentence which only leaves "es gut".
No, because in a subordinate clause the verb takes the post position. http://german.about.com/library/weekly/aa010910a.htm
Actually, it would be written in the same order without the capitalization. "Sofern du das essen magst, ist es gut." As long as you that [to eat] like, is it good. It's a subordinate clause with a single infinitive so the conjugated verb still goes at the end. If you want to do a little outside learning, read up on the sentence bracket, "Satzklammer". Word order can be tricky in German. People like to say word order is freer than in English and people are wrong :D
"Sofern du das Essen magst" is a subordinate clause. The conjugated verb goes at the end of the subord clause, as long as there aren't two infinitive to go with it, but that situation is advanced so don't worry about it yet. In this sentence, "ist es gut" is the main clause and "ist" is actually in the second position for the whole sentence. The whole subordinate clause is the first position bracket.