3ouncessharp white cheddar cheeseshredded,about 3/4 cup
3ouncesfontina cheeseshredded, about 3/4 cup
Remove lid from Instant Pot. Press [Sauté]; use [Adjust] to select “Normal” mode. When the word “Hot” appears, swirl in 1 tablespoon of the oil.
Add panko; cook, stirring constantly, 1 minute or until golden brown. Turn cooker off. Remove panko from inner pot; set aside. Wipe inner pot with a paper towel.
Add 3 1/2 cups of the water and pasta to cooker. Close and lock the lid of the Instant Pot. Turn the steam release handle to “Sealing” position. Press [Manual]; select “High Pressure,” and use [-] or [+] to choose 3 minutes pressure cooking time. Open the cooker using Quick Pressure Release.
Remove pasta with a slotted spoon; place in a medium bowl. Add milk, garlic powder, salt, black pepper and red pepper to cooking liquid. Combine remaining 1/4 cup water and flour in a small bowl; gradually add to milk mixture, stirring with a whisk.
With lid off, press [Sauté], and use [Adjust] to select “More” mode. Bring to a boil; cook 5 minutes or until slightly thick. Turn cooker off.
Add cheeses, stirring until cheeses melt. Stir in cooked pasta, tossing gently to coat.
Heat a medium non-stick skillet over medium-high heat. Add remaining 1/3 tablespoon oil to pan; swirl to coat. Add tomatoes; sauté 2 minutes or until soft.
Top pasta mixture with tomatoes and scallions; sprinkle with panko.
For a smooth sauce, be sure to combine the flour and water before adding it to the pot.