Chop strawberries and add them to a medium sauce pot, heating over medium heat.
Add sugar, vanilla and lemon juice. Stir well.
Cover and cook for about 15 minutes, stirring often.
Use your immersion blender to puree strawberry mixture. (If you don't have an immersion blender, use a regular blender or a food processor.)
**If you will be using sauce in frosting or some kind of cream filling, strain puree to get rid of leftover chunks.
Notes
Thickening the sauce: This strawberry sauce is pleasantly thick naturally because of the blended strawberries. Although, there are times when you want to thicken the sauce, like when your strawberries produced a lot of liquid or you want to keep it chunky. To thicken the sauce, use cornstarch and water slurry. When the strawberries are mostly done, mix a 1/2-1 tbsp (depending on how thick you want it) with a couple of teaspoons of COLD water. Once mixed, whisk it into the sauce and keep stirring until the sauce thickens. It it will only take a couple of minutes. Take off heat.
Storing: Make sure to let the strawberry sauce cool to room temperature first! Then, store it in an airtight (preferably glass) container in the refrigerator for up to 7 days. Always use a clean spoon to remove any as desired so you don’t introduce any new bacteria to the sauce. I recommend using a glass jar with a lid that’s not made of metal. Metal tends to react when stored with foods that have acidic elements. These are the jars that I use at home: with coated lids and with hinged lids.