How to Make It
Make crumb crust: Toss together graham cracker crumbs and 2 tbsp. butter in a small bowl. Butter two 6-oz. ramekins, then press graham cracker mixture into bottom of each ramekin, dividing evenly.
Make filling: In a medium bowl, beat cream cheese and flour with a hand-held mixer on medium speed until light and fluffy, about 30 seconds. Add sour cream and sugar and mix on low speed until smooth. Add salt, vanilla, and lemon zest and mix until just combined. Add egg yolk and mix until just blended. Divide filling between ramekins and smooth tops.
Bake cheesecakes: Pour 1 cup water into Instant Pot and place rack that comes with pot inside. Put ramekins on rack. Set Instant Pot lid in place and set valve to Steaming. On manual cycle, set timer to 4 minutes. Lock lid and let Instant Pot come to pressure and then cook. When timer beeps, Instant Pot turns itself off. Allow pressure to release for 10 minutes. Switch valve to Venting, then carefully open pot.
Using tongs and a hot pad, lift ramekins from Instant Pot to a cooling rack; let cool 30 minutes. (Any liquid on top of cheesecakes will reabsorb as they cool.) Cover airtight and chill at least 1 hour.
Meanwhile, hull and thinly slice berries lengthwise, then put in a small bowl and sprinkle with sugar. Let stand about 10 minutes for sugar to dissolve.
Top each cheesecake with a few strawberry slices.
Oven method: Preheat oven to 325°. Follow recipe, but skip step 3. Instead, place ramekins in a 9-in. square baking dish, fill with enough water to come halfway up sides of ramekins, and cover dish with foil. Bake just until set with a slight jiggle in the center, 30 to 35 minutes. Proceed with steps 4 through 6 of recipe.
Note: Nutritional analysis is per cheesecake.