To prepare chutney, melt butter in a small saucepan over medium heat.
Add onion, ginger, and chile to pan; cover and cook 6 minutes or until onion is tender. Uncover. Stir in pineapple and next 3 ingredients (through 1/4 teaspoon salt); bring to a boil. Reduce heat, and simmer, uncovered, 20 minutes or until pineapple is tender, stirring occasionally. Cool 20 minutes; stir in cilantro and red pepper.
Preheat oven to 40
To prepare pork, combine chili sauce and next 3 ingredients (through tamarind), stirring to combine. Reserve half of soy mixture.
Heat a cast-iron grill pan over medium-high heat.
Sprinkle pork with 3/4 teaspoon salt and black pepper; coat pork with oil.
Add pork to pan; saut 4 minutes on 1 side or until browned.
Brush pork with half of soy mixture; turn pork over.
Place pan in oven; bake at 400 for 16 minutes or until a thermometer inserted in the thickest portion of pork registers 155 (slightly pink).
Remove pork from pan; let stand 10 minutes.
Brush pork evenly with reserved soy mixture. Slice pork crosswise into 1/2-inch-thick medallions.