In a medium saucepan, mix sugar and Roasted Strawberries juice. Convey to a boil over excessive warmth, being cautious to not splash sides of pan, stirring to assist sugar dissolve. (Don’t stir as soon as combination begins to boil.) Cook dinner till an instant-read thermometer registers 240°F (116°C).
In the meantime, within the bowl of a stand mixer fitted with the whisk attachment, beat egg whites, salt, and cream of tartar at medium pace till smooth peaks type.
With mixer on medium pace, pour sizzling sugar syrup between aspect of bowl and whisk attachment in a sluggish, regular stream. Enhance mixer pace to excessive; beat till stiff peaks type and bowl and meringue are comparatively cool to the contact, 8 to 10 minutes.
With mixer on medium pace, add butter, a number of cubes at a time, beating till mixed. (Combination will look very free to begin and will even look damaged at one level, however buttercream will come collectively; see Notes.) Beat in vanilla bean paste. Beat till gentle and fluffy, 1 to 2 minutes, stopping to scrape sides of bowl. Fold in Roasted Strawberries. Use instantly, or refrigerate in an hermetic container. Let refrigerated buttercream come to room temperature and rewhip utilizing the whisk attachment till silky clean earlier than utilizing. (See Notes.)
