The second word in the Bible transliterates to "bara."
Create, in English.
Bereshit bara. When/in the beginning [God] created ...
The footnote to my LDS version provides also the synonyms "shaped" and "fashioned."
Those would be more conducive to the LDS concept of "bara" being carried out with pre-existent matter, not "ex nihilo."
I'm no expert on the whole ex nihilo (from nothing) doctrine or why "traditional Christianity" weds itself so tightly to the notion.
Richard Hopkins, How Greek Philosophy Corrupted the Christian Concept of God, finds no direct Biblical support for ex nihilo. (p. 290).
Ex nihilo is a purely Platonic concept, based on the idea that the universe was created from illusory matter having no being. (p. 295).