In a large bowl, whisk coconut oil, eggs, sugar, and buttermilk until smooth. In a separate bowl, combine flour, cornmeal, cornstarch, baking powder, baking soda, and salt. Fold flour mixture into liquid until batter is just combined.
Cook waffles in a waffle maker according to manufacturers instructions until waffles are crispy and golden-brown. Keep warm.
In a medium saucepan, combine strawberries, sugar, and lemon juice. Bring to a simmer over medium-high heat, smashing berries with a wooden spoon, then reduce heat to medium-low and let simmer covered stirring occasionally until berries are reduced and syrupy, about 20 minutes.
Serve waffles warm with strawberry preserves. Enjoy!