In a small saucepan, combine chopped strawberries, sugar, and water. Bring to a simmer over medium heat and cook for 10-15 minutes until strawberries break down and the sauce thickens. Stir in lemon juice. Strain through a fine-mesh sieve for a smoother sauce if desired.

In a medium saucepan, heat the whole milk and heavy cream over medium-low heat until steaming (do not boil). Remove from heat and add the white chocolate. Whisk until the chocolate is completely melted and smooth.

Whisk in the prepared strawberry sauce to the white chocolate mixture. Return to low heat and warm through for another 1-2 minutes until you reach your desired temperature.

Pour the strawberry hot chocolate into two mugs. Garnish with whipped cream, marshmallows, or sprinkles. Serve immediately.